Keep trying, over and over, until you either:
- Like what you get;
- Say "It's as good as it's going to get";
- or, throw the whole thing against the wall in frustration.
I've only ever achieved #2, but have come close to #3 a few times.
I'm working on a canopy now. I'm going to try a new tactic: Instead of trying to mask in the corners, I'm going to mask straight lines with Tamiya tape. Do the first set, allow that to really dry and re-mask for the perpendicular lines. Might have to make three passes, don't know yet. Might work, or I might make a mess of it.
Paul