Sadly my experience is mostly based on painting fenders on stacks of tires as a "paint booth" and painting my friends '72 Econoline camper while well into a 12 pack. However, we do manage to occasionally get a good finish out of it. Wet sanding the runs out of the base is something we do before the second coat of base. The smoother the base, the better obviously. We try to keep the base nice and thin, you only need enough base to have a solid colour that covers everything, the clear coat is going to do all the work. Time between coats depends on the temperature, how thick you sprayed on the last coat, etc. When it comes to the clear, I personally go for the 2 or 3 thin coats over 1 thick coat theory, as there is less chance for runs. Adding more is always easier than removing the runs without messing things up. If you aren't in a hurry, let stuff set overnight between coats, but we have done it with only a few hours in between and it hasn't fallen off yet ha ha
