My first puppet (And so far, only puppet) is a Fraggle styled one (Kinda based off Boober, but with some differences like hair and skin color and the type of hat). He's not the greatest piece of work, but hey, you can't get any worse.
If you do plan on making your own, I suggest doing a little homework first (Look for patterns, supply lists, suggestions from puppet makers, et cetera), and if it doesn't turn out like you planned at first, no biggie! Just learn from your mistakes or experiment.
Most of all, if you can, be resourceful. The aforementioned puppet was made using a pink Snuggie, if that can give you any indication. It works, and it's nice and toasty during the winter, but most muppet makers will use antron fleece, or if you can't find any, non pilling fleece works. Foam may be used for making the head and body, while ping-pong balls work well as eyes and ostrich feathers do wonders for hair. But like I said, use what you can and if you absolutely must buy something, go ahead and do it.