Monetary rewards are not as motivational in the long run as letting someone know they're doing a great job. Here are a few simple, free ways to motivate your employees:
Allow Them More Autonomy
Allowing employees to make more decisions on their own motivates them to be more responsible. Also, when employees are working towards a goal they set themselves, they are more motivated because they want to prove that they can do what they set out to accomplish.
Celebrate Their Successes