Oh I think you're doing just fine, a few paint runs are all part of the game. Leave it for a few days and then use 400/600 paper with very light pressure to take off the run. If you have a good depth of paint already I would be tempted to polish it (G3 cutting compound, T-Cut then polish) to see if it will polish out.
Everyone has their own trigger points when they stop adding paint. Mine is to put light passes which cover the panel with a solid colour and flash off quickly, then finish off with a heavier coat. It generally looks a bit orange peel and "not enough" when I stop, but gravity and paint flow usually smooth it out well enough in the 4/5 minutes it takes the thicker coat to become tacky.
Final polish with T-Cut and sometimes G3 cutting compound is normal with me I'm afraid, I'n not good enough to get a mirror shine everywhere straight from the gun because I just don't do enough painting. And there are always the odd kamikaze fly and dust specs to remove as well !