My rewards are praise, food, and affection/play time. She is 3 now, so praise usually works most of the time as a reward.
I sometimes use her favorite trick for praise. She has learned "high five" (she jumps up and hits your hands with her front paws). I've taught her that high five is for joyful times. So, if she does something good, I'll ask her for a high five as a sort of "that a girl!"
Sometimes I need her to do something quickly so I use food. For instance, her "come" command isn't the best yet. She always wants to go potty when I'm making lunch. She has to be watched outside because of her obsession with eating tan bark. So, in order to get her out and back quickly, I offer a baby carrot as a reward. You should see how fast she can do her business when a baby carrot is on the line. LOL
