As their manager, learn what motivates each person on your team and tailor your motivation techniques accordingly.
You'll find that most people are motivated by much more than money. Some want and need routine praise. Others seek public recognition for a job well done, while some people prefer less public acknowledgement.
Some employees are motivated by being given increasingly more challenging tasks.
You may also find that you'll have employees on your team who are motivated by being included on your decision making process when you establish policies or procedures. And still others are motivated by being given as much autonomy as reasonably possible.
So, observe, listen, and then tailor your motivation techniques for each of your employees, and be prepared to tweak those techniques if necessary as each person grows within your organization.