After reading The $21 Challenge, I thought I would see which other areas of my life I could apply the Challenge to.

First, I opened a separate bank account and now deposit $21 every week before I do anything else with my money. I see this as a type of retirement fund – it will be nice to see the funds in 30 years time!

My next $21 Challenge is to only put $21 worth of petrol in my car each week. I will park my car further away from where I need to go; this will save money and improve my fitness and wellbeing.

When my phone contract ends soon, I am going to challenge myself to spend no more than $21 on pre-paid phone credit each month - now that will be a challenge!

There are so many ways we can implement the $21 Challenge in our lives, thanks to Fiona and Jackie's inspirational book.

About a year ago my husband and I were having lunch at a seaside cafe when we noticed the people next to us paying their bill with $5 notes. We found out that they were on a trip around Australia and every time they were given a $5 note, they saved it and used it toward their food bill.

Thinking this was much better than saving $2 coins, I started doing the same. As soon as I receive a $5 note in my change, I pop it into my purse and then put it in a money box when I get home. I keep track of how much is in the box by writing the amount in my diary; when I get to $500 I empty the money box, take it to the bank and put the money into a term deposit for a rainy day.

So far I have saved $1435! I never miss the money and most times I go shopping I come home with at least one $5 note!

My kids love doing things on Saturdays but even a trip to the movies for our family costs $70. So I invented '$20 Saturday'. We could go anywhere and do anything as long as it didn't cost more than $20 for the whole day. One Saturday each month we would find a spot in the street directory that looked interesting and take a picnic, other times we visited free places such as museums or community festivals and the $20 bought a drink, small snack or ice cream. Not every place was terrific but we gave each place or activity a score to rate whether we would like to do it again. My boys talk fondly of things we did together and places we visited on $20 Saturdays and they learn that you don't have to spend up big to have fun.

We are retirees. We eat well, dress well, and live in a modern house, with an interesting flower and vegetable garden. Our income would probably be classed as poverty level, but we live like kings, because we have one shared vice. We are garage sale fanatics. Little in the house has been bought new. Older furniture has been restored, as my husband has clever hands. Once a year he sells the surplus at a huge garage sale, and it usually pays for a holiday.

We buy books, linen, furniture, new clothing, garden plants, sewing material and cottons, timber for building toy boxes and hall stands at garage sales. Our kitchen TV cost $25. The little one in the bedroom is 25 years old, so I bought a video recorder for $5.00 and can now get all the channels through the video. My three telephones and the answering machine are all from garage sales, as are my kitchen crockery, blankets and the beautiful satin embroidered bedspread that cost $5.00.

I am like a centipede with shoes as I buy good brands that have been tried on in the shop and are as new. It is the only place I can find the good comfortable shoes I favour. Likewise, many of my clothes are top brands. I bought a $168 pant suit for $10 because the lady's husband didn't like the colour.

The deep freeze, the two coolers, bed lights, beautiful big mats are all from our Saturday morning treks. We list the sales and use a street map to plan a route to save petrol.

Sometimes tinned food or home-made sauces are available, and if the vendors have fruit trees they sometimes sell the fruit by the plastic bag - picked yourself.

Nothing is sacred at garage sales, and provided you need the items there are some real bargains.

How about our home security system for $2.00, because the seller couldn't work it? A little investigation on the Net yielded full instructions.

My computer came from a government auction at one-third of the price quoted for a second-hand model at our local shop. Needed a bit of study to set it up, but I love puzzles, and so had it running with the Windows 98 program I bought for $10. I also keep the grandkids in Playstation games, and my daughter has been married for 20 years and has never bought any linen as I have kept her supplied with good quality buys.

My hobby started after my divorce when I found myself with an old 50's house to renovate and little furniture. So I started to buy 50's vintage furniture as well as renovating materials - paint, wallpaper, timber, doors, curtains.

Along the way I met a widower with the same ideas, so garage sales have provided a lot of rewards - a good life, enough money to enjoy ourselves, and a multitude of associated hobbies and friends.

My husband and I have began saving up to $30 per week on our grocery bill since we invented 'Grandma's Day!' When we go to the supermarket we ask ourselves, 'would Grandma have been able to buy this item in her day 60+ years ago?' If the answer is no, then we decide we don't need to buy it either! This saves us money on a whole range of items such as fancy dips, designer coffees and biscuits. We used to pay over $3 for a pack of 10 biscuits, now I can make 12 biscuits for around $1. Using plain yoghurt as a base we are even making our own dips; there are so many websites with great dip ideas. Now we are saving valuable money and our waistlines too!

Make over 120 bickies for just $4.00! This fantastic basic bickie recipe is terrific value, makes loads and has lots of room for variations:

500g margarine
1 tin condensed milk
1 cup sugar
5 cups self-raising flour

Cream sugar and margarine. Add condensed milk and flour. Roll into teaspoon sized balls and press down with a fork. Place on greased trays and bake in moderate oven until golden brown (approximately 10-15 minutes).

Before baking I divide the mixture into five and add the following ingredients for different flavoured bickies:
1. Chocolate chips and glace cherries (chopped)
2. Cornflakes and sultanas
3. Hundreds and Thousands
4. Jam drops
5. Milo and coconut

You could add any number of other things like Rice Bubbles, Smarties, nuts, cinnamon and other spices and so on. The raw mixture can be frozen in balls, just thaw slightly before baking.

From this one batch we made 123 bickies and by my calculations using the cheapest possible ingredients, the whole batch cost just over $4.00 to make!

For many people juggling work, family and study, time is the most important saving they can make. I work four days a week, have a three-year-old and studied part-time for a diploma for a year. I got by with these time-saving tips:

1. Lowering my expectations for the house. I don't need a spotless house, but a tidy and lived-in home.

2. Doing my housework little and often, rather than spending huge amounts of time tidying up. I do things like:

- put my little one's daycare bag together for the next day as soon as we get home in the afternoon.
- cook my lunches (pasta and sauce, muffins and so on) once a week and freeze them.
- put my lunch box together from the freezer in the evening.
- clean the toilet by putting a teaspoon of Napisan in it each night. It soaks overnight and the bowl is clean with the next flush.
- do laundry when enough for a load accumulates so we don't have a sudden clothes drought, then an avalanche of laundry to do and put away.

3. Exercising on a stationary bike in front of the TV in the evenings after my little one is in bed.

4. Programming our DVD recorder once a week (Sundays when we get the new TV guide) so I don't miss my favourite shows.

5. Filling cereal bowls with water if I am rushing and have to leave the breakfast things. This makes them easier to clean later and stops ants.

6. Trying not to double handle things. Rubbish goes straight in the bin, meat is put in meal size portions in plastic bags and frozen as soon as it gets home, magazine subscriptions go straight to magazine rack when they arrive in mail.

7. Leaving rooms better than when I arrived, so the need to tidy doesn't build up. It only takes five minutes to put laundry from the floor to the hamper, make the bed, wipe a bench, replenish the toilet paper.

8. Recruiting my little one to help - she's only three but she can put dirty dishes in the sink, put toys away in her room, dirty clothes in the hamper.

9. Shopping for groceries by myself in the evening so hubby can watch his TV shows in peace and I am not tempted to go to other stores as only the supermarket is open. Also many things are marked down at that time.

10. Trying to do three things for myself that make me feel happy each day, like listen to podcasts while I do the housework.

11. Writing the shopping list progressively through the week so I can pick it up and go when it's time to do groceries.

12. Storing the bedding in storage containers under each bed so it's quick to make the bed, especially when changing my little one's wet sheets in the middle of the night.

13. Shopping for presents at sales during the year (online or in stores) so I don't need to go to crowded stores during the Christmas rush.

14. Not beating myself up if I find lifestyle changes tricky at first - I am afterall human!

I am no longer wasting leftover avocado, thanks to this simple storage tip! I have always loved avocado but could never use a whole one in one go. I would use about a quarter for my lunch but by the time I went to use the rest it would have gone brown and didn't look very appetising! Avocados can be quite pricy so the expense of wasting so much was very annoying. Then my new partner, who is chef told me how to stop the browning! I didn't realise but the longevity of avocado is due to light. He advised me to wrap the avocado in aluminium foil and then wrap it in cling wrap and put it in the fridge. To my surprise it really works! Now I get to enjoy ALL my avocado and save heaps too!

Follow Jamie Oliver's example and make your own chicken nuggets - it's healthier and cheaper! We used to buy the cheap brands of chicken nuggets but after realising how much of their content was fat/skin/fillers and other unmentionables, we switched to only buying breast nuggets or pieces. However, this soon proved really expensive and they often still have fillers. So I came up with a better way and found this home-made version is much tastier too!

Buy chicken breast fillets or tenderloins on special - I usually get them for between $9 and $10 a kilo. If using breast fillets, slice them into smaller and thinner pieces. Remove the tenderloin as one piece, then fillet the chicken into similar sized bits. Dip them in melted butter, then roll in breadcrumbs (press on firmly). I often use hot and spicy breadcrumbs, or stuffing mixes to add more flavour to the crumbs, but you can just use leftover stale bread crumbed in the food processor and save even more money! Layer the chicken in baking paper, then cover in plastic and freeze until frozen. Remove and separate into ziplock bags or suitable storage container.

When ready to cook, place in preheated oven and bake at approximately 200°C for half an hour, depending on the size of the pieces. Small boxes of prepared commercial fillet pieces/tenderloins cost approximately $7.00 for as little as 400g. In comparison, a one-kilo batch for $10 makes at least three times that amount - and without any junk fillers, additives and skin!

My husband and I have become '30 Day Gourmets' and enjoy both the savings and the extra time we spend together as a result! We recently looked into 'Once a Month Cooking', which we were interested in because neither of us really enjoys cooking tea when all we really feel like doing is relaxing after being at work.

After gathering ideas of how the scheme works (literally - you cook once a month!), we thought we would try it by cooking for a fortnight first. We gathered recipes from the Internet and raided the recipe books (the recipe must be able to be frozen) and came up with such things as marinated chicken, curried sausages, spaghetti sauce, apricot chicken and all kinds of things.

We then picked a Sunday, turned up the stereo and did nothing but cook! It turned out to be a really enjoyable day. Once cooked and cooled, the food is put into freezer bags or takeaway containers (which cost almost nothing) and frozen. What we thought would last two weeks actually lasted three!

Each night, I would take out a container or bag for the next night and leave to defrost in the fridge. We then dragged out the steamer, threw in all the vegetables and once a week cooked up a big pot of rice. We would then have a small portion of meat (which also lowers fat-intake levels), have a pile of yummy steamed vegies and a little rice - the result being full bellies, smiling faces and very minimal washing up!

This not only saved us money but also time. Usually groceries cost us $150 for two weeks. With the cost of buying meat and grocery items needed for the cook-up ($100) and in-between buyings of vegetables once a week ($10), we spent a total of $130 when we would have spent over $150. (This is because at each shop we would grab things we liked, but didn't really need). Having a selection of meals already cooked for the weeks ahead feels great!

At first a big cook-up seems difficult if you aren't motivated, but you can start small and next time you are cooking something that would freeze well, cook double or triple the recipe and freeze excess. I also went to the local library and got out some books on freezer cooking which also had suitable recipes in them.

My husband and I honestly can't believe how we survived before our cook-ups and love the idea of actually doing things we want to each night, rather than being a slave to the kitchen!

NB - A book from the library which was a big help in planning recipes was 'The Freezer Cooking Manual from 30 Day Gourmet'. The '30 Day Gourmet' book is available on eBay and from most bookstores.