Like he said.

Hidden places first.

I start roof, then hood & Fender Tops, Trunk lid & Quarter Tops, then shoot the whole side (as best as possible) as one long shot. My theory is paint falls down and shooting the bottom last will cover any falling over spray with wet paint.

I like placing the car stands to better to better shoot the lower rockers and I keep small easy to move step stools/ladders to help shoot the roof.

Keep the hose over your shoulder, good lighting, have a board/ paper target to adjust the gun before you get near the car. Don't adjust the gun on the car. Tack right before you shoot and clean the floor religiously.

The trick for metallic for me is stir the paint before each refill and if the gun sits for too long. I shoot the first coat light and diagonally then the second coat horizontally. Overlap.

There are better painters on here than me but those tricks have always done me well.