Step 1. Get hat with a bill(RF hat or similar)
Step 2. Get hand towel
Step 3. Put towel on your head so that it it wraps around your face.
Step 4. Put hat back on.
Bonus step!!!! if it's a super hot day(90 degrees or more with like 100% humidity, simply soak the towel and or hat with water. also use any novelty or theme based towel(AO, FO, Wimby, USO ect...
It works great for watching a tourny but for playing I wouldn't even wear the hat the ball kids are.
Dreaming of the Robin Soderling comeback 2013.