Every year, as a volunteer with my church's youth ministry, I say goodbye to the -tremendous- seniors graduating. It's rather bittersweet... a kind of "boo-hoo/yay!" seesaw if you know what I mean.
There's quite a few graduation parties that go with the youth group territory and a few years ago I came up with an all purpose gift idea that's served me well.
On the day of the graduation party I gift a coin envelope in the style of a "miniature" gift package. Then, at some point within the next school year, I post a bubble mailer full of goodies their way.
Personal but doable if you're a fan of a lot of seniors.
Cheerio Class of 2013! May you abide in Christ your life-long.