If you leave the game wishing you had given a T, you most likely should have. Give warnings - but you have to back them up by enforcing them, if necessary. Don't let coaches get personal or distract you.
I know that I got the best idea of what deserves a T and what does not by working with a more experienced partner. Seeing what he let slide and what he T'd up gave me good guidelines to build off of.
I'm guessing if you have only given out 2 T's in 200 games, you might be taking more abuse than you should.
But what do I know? Maybe you just have amazingly good sportsmanship out there.