The Golden Pez Dispenser
This is a low cost and fun way to encourage students. It also has the added bonus of giving your small group leaders an opportunity to be creative as well. Spray paint different Pez Dispensers gold, and have small group leaders pick out one of them to give to one specific student in their group. When they give them out have them creatively connect the reason to the Pez Dispenser they chose. I encourage them to choose a student that often gets overlooked. This gives us a chance to encourage those "middle students" (to find out what that is check out episode 2 of our podcast).
We do this during the last session of our winter retreat in front of the whole youth group. It encourages students, and gives a chance for our small group leaders to be creative and encourage. This has become a fun tradition that our students and adult leaders look forward to.