I have it down to a routine with the Windows calculator:
Enter yardage to target (either indicated in the GUI, or determined by me for the required shot).
Divide that by the maximum yardage of the club my caddy hands me.
Multiply by the length of the power meter (only the part where the power bar actually starts on the right to the extreme left: for me it's 73.5mm for all clubs except my putter which is 72mm).
This gives me a BASE power meter setting (in mm's).
I then adjust for my lie (nothing for fairway or add a few mm per length of rough cut, etc.), the wind, elevation, green speed and contour(s), etc.
Then I decide on whether to use that club, or shoot my caddy and select the correct club and re-calculate.
Then I use my 150mm ruler and place my thumb at the required power point on the meter.
Haul back to that point and whack.
For putting I sometimes add a bit of power for drastic off-dinging, especially if I have to move the target marker for extreme green slopes.........
I can usually do it all in about 30 seconds, and it's sort of a combination of automation, skill, and experience from practice.