First things first--free beverages. I believe that your employees should be able to drink as much of your coffee as they want. If you want them to be brand ambassadors and be able to speak in a knowledgable way about your products, they need to experience them. At our cafe, employees can come in on their days off and they don't pay for their coffee. We give a 50% discount on all food, as well.
The big thing here is to find incentives that fit your company culture and values. How do you want to engage your employees?
Does your roaster offer trainings that people would be interested in? Have you taken your staff to trade shows?
Have you encouraged them and rewarded them for participating in competitions or throwdowns?
Could you get them a custom apron or tamper made?
What about an educational credit toward professional development on an annual basis?
This is just a start, but it hopefully gets you thinking about how you want to engage your employees and keep them motivated. Best of luck!
That's a really awesome idea, Jordan!