Are you falling into a training trap? Always asking your dog for the same things over and over?
Think of all the behaviours your dog knows -for example: sit, down, wait, stay, roll over, touch, bow, etc. They can even be combinations of behaviours - such as: sit/stay while you walk around your dog. Mark them down on small index cards and put them in a bowl or some other type of container.
Before you go out for a walk or put the food dish down, grab a card out of the bowl and ask for that behaviour 
You never know what you are going to get!