I went simple with my cards this year, as I just don't have the energy to do anything elaborate. It helped that I found some mortarboard stickers in my ancient sticker collection. I used the students' school colors for the cards.
I cranked out 5 of these this year. I'm enjoying making the round things. (Yo-yos? Not sure what they're called.) Super simple with a single strip of paper and a scoring board.