I don't like watching shows where embarrassing things happen to characters. I get uncomfortable. I realized, when I was looking over the last few chapters in my young adult novel, that I avoid embarrassing my protagonist. Through this realization, I know exactly what I must do to my character-- embarrass the crap out of her.
I've had embarrassing moments in my life that I've never forgotten. Some I did to myself, other instances it was the people I was connected to doing the embarrassing things. No one likes to appear stupid, and most people avoid it at all cost. Therefore it is only fair to make my character squirm a bit so she learns it's human to make mistakes.