I'm constantly giving Jackson treats because we do clicker training, trick training, agility, etc, so I always use either real meat (like pieces of boiled chicken) and I buy those cheese sticks that I break into little tiny pieces.
As for dog treats, I use
Zuke's (they're small-about the size of an eraser, and about 2 calories a piece) or "
Canz Real Meat " and break them up even smaller.