Homemade cake balls:

At school, our Student Council gave baggies of Jolly Ranchers to all of the staff:
~Mrs. Scott

They were given to my 8th grade math students, which was even more effective b/c with around 100 students, they obviously don't all get to test with me. I thought some might find it cheesy, but even my toughest students wanted one and held on to it.
After test scores came back a few students who had never passed before, finally did, and attributed it to their lucky pencil! Since then, I have continued the tradition.
I purchased mine from Oriental Trading costing $17 for 72 pencils. Let me know if you find them somewhere else for less.
The reusable cups with lids are for them to take to their classes each period without having to worry about spilling. We found as many flavors as we could of single use lemonade and limeade.
Lotion - "Hope you have a smooth year!" - website even has multiple printables to choose from.
Air Freshener - Would change the wording to say "Hope you have a SCENT-sational year!" You need to check out this blog b/c they have a lot of other great suggestions.