ideally you would get an alignment every time you re adjust the height, but instead you should just put the height nearest what you will mostly drive at, and get an alignment that way. For Example if I had coilovers I would have a show slam look, then a daily driving height, and then a man this area of town sucks because of it's bumps height.
so that's three heights, but I would mostly drive on the bumps and daily driving height, and never really drive on the slammed car show height. Therefore I would put the height just between the daily driven height and and the 'wow these bumps are huge' height, but moreso on the daily driven height, then get an alignment.
So whenever you are at daily driven height your alignment will be correct and yoru tirtes will wear normal, when at bump height, your car will wear only a tad abnormal, but not a big deal. At car show height you will want to drive as little as possible, if it is even drivable. heh. Understand?
