Contingency Contract

or If ---> Then

Think of something that you were going to do for or buy for your child anyway. Then gather paper, pencil and your child. Brainstorm together about the contingency, if______, then__________. 
For instance, you might say that they get one sticker, or one marble in the jar, for each complete practice session. Once there are a certain number of stickers or marbles, your child gets the prize. One of our parents set up a program where it takes a certain number of points to get a $3 prize, another number for $5 prize, and still another for a $7 prize.  She keeps the plan going for as long as it works.
Remember, all of these practice tips are valid, but usually what works for a week or two or three, won't work for six or eight in a row! The trick is to do the change up before they lose interest with the tip/strategy you're currently using.