Today, I built new wheels for my latest R20. Sharing the experience will hopefully be of interest. I'm no great expert, and have never done it professionally, but I worked for several years alongside two master wheel builders from whom I picked up some useful hints and tips. They both no longer work in the cycle trade, and I don't trust anyone else to do it properly, so doing it myself is the only option. I build all of my own wheels. I would feel honoured if either of my two ex-colleagues were to rate my own efforts as adequate. To get really good at it, you need to build a lot of wheels and do it regularly.