I would say "don't panic" if you get some orange peel, specially if you have enough coats of clear. If you are painting at 70 degrees or warmer ... use the slowest reducer possible, the slower the better in my opinion. I have some direct experience with this from painting on a late afternoon when the sun had warmed one side of the car a tad more than the other ... the warmer side had noticeably worse peel as it didn't have as much time to settle down.
The finer mist you can get the better ... but I gotta admit I had a hard time making that happen with a Iwata gun with a 1.3 without using about 30 psi. (although that was at the gun inlet, no idea what it was at the cap).
Regardless, some orange peel just means some quality time with your car to get to know all it's curves
