How about spacing? 10 yards 50 yards 90 yards. Or do you put at close to equal distance 30 60 90 for 100?
With 3 to 5 flags I’ll usually 20, 50, 80 out 110 150 to 200
With 4 Flags 20, 40, 60, 80 for 100 yards then add 100 and 150 for 200 yards.
Also as Mike touched on I’ll place a flag on what I consider to be key terrain such cut in the berm or trees.
When setting flags I set the farthest flag first centered on the target and place the others at a slight angle as they get closer to me. I also stair step the height of the flags So that I can see the entire flag and flag tail while I’m down on the gun. I shoot with both eyes open and try not to blink while shooting. This way I’m watching the the flags and crosshairs at the same time.
Seldom do I key in on one certain flag. I’m am looking for a flow/condition. Look over the entire field of flags and see where the condition is coming from. Time how long it takes to get to you. That way you can judge how much time you have to shoot your group.
Or if you see a change coming from across the range you can wait.
Note what type of condition you shoot best in! Also note what condition hurts you the most and try and avoid it. For me the condition that hurts me the most is a let-up!
As far as how many flags to use... that’s up to you. There are no right or wrong answers. I’ve gone to 3 and 5 because it’s a cleaner set-up and plenty enough info without getting over loaded. The vast majority of group shooter use 4 and 6 because it’s the Boyer method. But I’ve seen 8 or 9 at 200.
One last note! If there is a flag that keeps getting tangled up with its flag tail, that’s a problem spot on the range.
Bart