George, you've made me feel guilty! I started making my own floats several months ago, and haven't used a shop-bought one almost since I started. I used lots of information sources, including Bill Watson's book, various threads on FM (including yours) and other stuff I google'd.
To date, I've bought all the bodies I've used, rather than make my own (except for a few pike bungs from balsa dowel), and have used wooden skewers and quills from peacock (eBay), crow (eBay and found), goose (a friend's birds) and pheasant (shot my own). I either use black plastic bases, or lengths of round toothpick or skewer, in bodied floats, and toothpicks or thinner bits of quill for inserts. I've also made some loaded wagglers with short lengths of brass rod: judging the length to use for a particular piece of quill is the hardest part, and I haven't quite mastered it yet. I've experimented with brass, nickel and stainless steel eyes, but only anticipate using it for the upper eye of river sliders in future.
I've made some failures - bodied waggler style, using skewers that were too heavy and stopped the float cocking until the entire shot load had settled. Other than that they've all been successful. They've worked and caught fish regularly, which has given me confidence to continue making and using them.
Paints/varnish are where I've had most trouble. I used a water-based model-making varnish that dissolved, and another that dissolved the paint. I've ended up with Revell Email Colour matt paints (yellow, orange, black) and Morrell's laquer. I stain my bodies with a wood stain, and have learned to stain them before gluing in the stem, to avoid glue smears from stopping the stain taking. I use Araldite Rapid, as it has body and fills holes/gaps well, or PVA.
Next? A Unimat lathe I think, and some experiments with cork and dowel: shaping stick floats by hand with sand-paper is tedious in the extreme!
My favourites? Crow quill avons and onions - they just look so good, and work extremely well.
Why do I do it? For pleasure: I enjoy making things. Certainly not to save money! Floats are a tiny proportion of my fishing costs: memberships, licenses, rods, reels, bait add up to many many times the cost of the floats I'd get through in a season, and the total material cost surely exceeds the cost of using shop-bought floats. But who's counting?!
Thanks for asking the question and provoking a reply.