I've rehabilitated enough old wheels that I've a) gained plenty of experience and b) learned to fully detension/fully loosen all the spokes and start over. It's the only way to ensure the nipples are free enough to fully do the job. Scary huh?
Another valuable lesson I read was: it's more art than science. Don't even try to get it right the first time. Work a bit in one section or on one side then back off and work somewhere else. Stop and breathe, check it here and there then correct something. Take your time. Warm coffee, good music, fully alone in the shop.
Approach truing wheels like an art history major, not like an engineer (says the Engineer). My goal now is < 2mm of hop, < 1mm off dish and < 1/2mm of runout. And I can get that with a good rim.