I saw on a blog (but didn't take note straight away so can't tell you which) that you can make buttons using Fimo paste. It is like a playdough, you can mix the colours but at the end you put it in the oven for 20 minutes at 100C, and you get real buttons.
We, me and DD1+DD2, made the shapes and then punched the holes. It was fun, still experimental, and we have a big result. Not up to selling standards, they are all different sizes.
That's my hand, to show you the sizes and shapes.
You only need a minimum to start : a sharp knife to cut the paste, something to make a hole, and websites suggest small cake cutters to cut shapes. We just bought some, haven't tried yet.
I hope this makes you want to try it. It is great fun, you can do it with children, and you can use them afterwards on bags, as decorations, etc...