Another good tip to having true wheels last is to avoid spoke twist at all cost. Often, once you get up to higher tensions when you finish building your wheel, you will turn the spoke wrench, but the spoke actually won't tighten on the threads because it twists in the middle. When you get out on the road to ride for the first couple weeks, you start noticing your wheels going out of true often. So avoid spoke twist!
One good method, once you get to higher tensions, is to overtighten the tension on the spoke wrench, then back it off. That is, overtighten the spoke, then loosen it all the while making sure you have roundness and lateral true.