FWIW, at various times my sons asked me what I thought was the best psych for doing their best on standardized tests (such as the SAT or graduate school entrance exams.)
I told them: Back in the day, I outperformed friends of mine on the SAT, though they were as bright--or brighter-- than me. I think it's because I intentionally approached the SATs as a game, as if I were solving riddles during a family car ride.
My older sons had decent mental attitudes for baseball, but they're amazed by my youngest son. He has a phenomenal attitude. He works his tail off, but treats it as a game. His teammates feed off of it.
Prior to a business negotiation, I try to tap into this approach, so that I won't choke.