To duplicate a factory-type look, here is the way-best done with the car not assembled, fenders on, not much else.
Get it as high as possible. (On the line, it was done by a guy in a pit-which had to be miserable.) Mask nothing. Mix the paint by eye in a coffee can. Cover the gauge on your spray gun with tape. If you are right handed, spray with your left hand. If you wear glasses, remove them to spray. The actual spraying should have no more than 60 seconds devoted to it.
But seriously, the things to remember...
No body color visible through the grille.
Nothing was masked and overspray was often abundant.
Horizontal surfaces should have no blackout on the TOP, because it was sprayed from below.
In practice, pattern, coverage, and even paint mix varied widely between plants and even shifts.