Materials: All you need is some paper punches, shrink plastic and some sharpies/permanent markers.
I used 1 cm paper punches for the gummy bears in the picture. You can use larger punches; they'll just make larger sweets. As for the shrink plastic, you can buy sheets of shrink plastic, or you can look around in your recycling for some clear plastic packaging. All you need to do is make sure that you can see this symbol on it:
The other types of plastic don't shrink. Once you have your materials, just punch out some shapes. If it gets too hard, punch some aluminium foil to sharpen your paper punches.
Colour in both sides with your permanent marker.
And bake in the oven for about 3 or so minutes. I use a little toaster oven. I recommend keeping a close eye on the plastic as you are baking it and taking it out as soon as it stops warping and shrinking. Also, bake on a piece of baking paper. And ta-dah! You've now got some teensy tiny candy pieces, perfect to fill up your miniature trick or treat bags with.