I have shot the 1500 round and 2500 round TPC classes. If you use gloves, I have found golf gloves and Mechanix Wear 0.5 mm gloves work well. My favorite is the Mechanix Wear.
I also occasionally use flexible band-aids. Don't use the cheaper brands, you get what you pay for. Besides the straight, get the other shapes too.
But my go-to solution now is
New Skin. I put it on my under-the-trigger-guard finger, the web knuckle and the palm. Those are the spots that rub for me. When you use a forward cant and grip properly those are the pressure points. I put on several layers, drying in between.
Oh, and take plenty of notes. :p