The other part of this that is very important is that for something to be motivating, it has to be something that they don't get everyday or whenever they ask. I can't tell you how many parents I have had in my office who make this mistake. A very common one is using money/allowance as a reward. This will only work if you do not buy your child anything or give them money for anything except for when they have earned it. Because this is so hard to do, I try to steer parents away from using money as a reward for the purpose of a behavioral management plan.
The best way to help ensure that the rewards will be motivating is to ask your child what they want the rewards to be. Odds are if they help you develop the reward they will be motivated by it.
I will discuss what types of things you can use as rewards in my post on the 21st.
(Any questions regarding topics discussed can either be asked in the comments section or you can email me at email@example.com)