Practice will certainly help one get to be a better builder, and probably to learn some better methods. I think a reasonably technical person can build a first rate set of wheels first time out, and with not a lot more than a spoke wrench. Otherwise, in the touring world who wants to serve a long apprenticeship with a trail of busted wheels behind one.
Basics are
1) find a compatible parts formula, you can copy stuff on websites that do custom wheels, there are often recipes. Some of the better stores will also have reliable info, but you have to be careful that they really and truly know, and deal with high mileage users like tourists, or messengers.
For instance on the last 4 wheels I built, I got components from Spicer. I had just finished reading Scharaner, and was all gung ho to use washers, but he said that I was using white hubs and wheelsmith spokes, and that there was no way I was going to have a problem, and he was so convincing I gave up on the idea. Though, Scharaner uses DT hubs and spokes which are made for each other, and absolutely top drawer...
2) brass nipples, stainless spokes probably wheelsmith. Spokes and rims can be recycled indefinetly, but you will have to do it yourself, and you must preserve the pattern of the previous build.
3) research the tension your wheel needs to be built to, the makers will have this info up to a point. Consider buying a tension device like the park. Some rims require working up to the full tension, Brandt has that method, however a lot of newer rims will not work with that.
4) find some instructions, Sheldons are fine, but do not rely on the stress relieving. Nothing crazy cross three, or whatever works if you are using say a Rohloff.
5) figure out how to true your wheel, and how you will determine if that has happened, will you use or make a jig, or use the frame, etc...
6) Come up with a stress relieving method. The Jobst Brant method of grasping parallel pairs should be part of it. I do 4 separate processes.
7) Have a method for dealing with the uneven rigging angle in the rear of the wheel. I use several methods, they all work, so you can find your own.
8) build and enjoy.