Seems to always be talk of what board to get on here, but not a lot of tips to actual surfing. So, I'll throw this one out:
I was surfing (surf style) last night and was again struggling with 3s. I'd go 180 and the fins would catch and game over. I was getting very frustrated because I did 3s last year and haven't rode away from one this year.
Then I made the discovery. My back foot wasn't back far enough. If your back foot is ahead of the fins, you'll end up pushing the fins sideways into the water, which will put on the brakes. Move your foot all the way back and behind the fins and now the fins become the piviot point to help you spin. Made all the difference in the world for me