Write student names or numbers on each pin and start each day with them all clipped to the main section. Then students are asked to move them up or down throughout the day based on behavior. Write the rewards and consequences on each section so students know what they are. You might also make a list of reasons student might move up and down with the class and also let them know the list isn't all encompassing and that students won't get moved up for every little good thing they do. Otherwise, you may gave students pestering you to move them each time they feel they do something right.
Here are some ideas for some rewards that are non-food rewards. A move to pink might have a reward as simple as a high five from the teacher and a move to blue in one day might be a point on a point card. When a student receives 5 points, they can turn in the card for a prize box pick. A move to yellow might be a warning, orange may be a reflection sheet and red a call home to parents. The purple could also be a call home to parents to tell them how great their child is doing. Just be sure whatever you choose, you're willing to follow through with it. Here are some links for reward ideas:
http://www.clemson.edu/extension/hgic/food/nutrition/nutrition/life_stages/hgic4110.html - Love the zero cost list on this site
These books are also great resources on classroom management. (Click the covers to see them on Amazon)
The last one is from fellow blogger Angela Watson of The Cornerstone.
Perhaps some of these ideas will be helpful to you as you return from your Winter Vacation.