When I directed an independent youth-media program, money was always tight. I wished I could give bonuses to both my part-time employees but the numbers just couldn't support that. Instead, I would add a personal check to their holiday cards as a way of saying thank you and showing my appreciation for their hard work. I couldn't give much, but I do think the thought counted for a lot. While I'm no longer a part of the business, one of those employees is at its helm and has been for more than 10 years.
All of our employees also get their birthdays off and a special party and celebration for them. Also, around the holidays, we normally go to see the CSO or some other symphony as a break for all the extra holiday work. :)