Wah Building Advice

[GammaFlex]

So I've decided that I'd like to try to tackle a wah, not exactly the easiest thing I think but I like a challenge. I'm looking for some advice as to a good beginner's project with some ability to add changes and such. I'm liking the idea of doing something similar to a Drive/Wah like in the same vein as the old Fender Fuzz/Wah.

So any advice as to what to do and what not to do?