If you are going out for a walk, collect colourful leaves. Place them between newspaper sheets and then place the sheets under a thick book and leave for about a week.
Get a bunch of old candle stumps (not too strong colours), place in a regular pan and melt on low heat. Remove any bits of the wick.
When the candles have melted completely, take out the leaves and dip them in, one at a time, and make sure each gets completely covered, then shake of excess and place on a greaseproof piece of paper. Each dip takes only seconds and it takes about a minute or two for the leaf to dry.
This will preserve the leaves and their beautiful Autumn colour and they can be used for decoration around the house. If you have the time, you can make a pretty wreath, or like I did a couple of years ago - just spread them on the mantle piece.
It is very important that the leaves are completely dry when you start. If they are "fresh", it's likely they'll go brown or worse - rot underneath the candle wax.