Personalize rewards to their recipients. Rewards should be valued by the performer. Make sure everyone can win. Reward programs built on the principles of competition or compliance are counterproductive, if not downright destructive. Make sure that rewards are contingent.
Reward programs become entitlement programs when they lose their contingency on performance.
Don't expect success all at once. The process of developing an effective program is one of change and continual improvement. Do it from the heart. Rewards that are intended to be manipulative are not accepted by employees. Have fun while you are doing it.