A little break from crying over spilled milk.
When playing a practice round, I keep two extra balls in my left pocket.
If the first shot is executed the way I wanted it, I move on. If not, immediately drop the second ball and repeat the same shot intention.
If that second shot is good, the first shot is noted as head issue to fix. If not, drop the 3rd and repeat the shot as if it was the first, including set up, etc. That's the suck test.
If the 3rd fails, then there's work for the range.
Unless playing for dough, playing just one ball for some official score doesn't help separate the head issues from swing mechanics issues.
3 ball. If the two balls never come out of your pocket in a round, time to go to some Q-School.