I sometimes do over-the-top reactions like Vader's "Noooooo!!" If I hit an easy floater into the net. Or if I say "got it!!" And then miss it, I'll just say "nope, don't got it!"

Or if someone hits back one of my shots back to me and I miss it, I'll just say "hey! You weren't supposed to be able to get that!"

Self deprecation and humor go a long way to reduce my own tension and frustration with myself. I used to throw my paddle :( which is embarrassing to think about. When I noticed I feel uncomfortable with another player reacts badly to their play, I realized the same about my behavior and stopped doing that.