Augment your wind flag experience with what you were doing on post #14 (follow the strings).
Remember wind flags are probably not going to be present on a Field Target course.
BUT ...Strings will always be there (for now) and may give you the most information along your pellet's flight path.
If you are only going to shoot locally, I would find out what type of string(s) they use and buy some to see how they behave in different wind conditions.
If you are going to shoot Grand Prix. I would buy different strings, set them at different distances and just watch how they behave in the wind (even in the rain...if you are competitive like me). You are also watching what the leaves, branches, and grasses are doing and finally where your pellet is landing.
I hate those skinny Dacron ones with minimal wind drag.