Inexpensive gift idea for ex without making it awkward ... ? Please Help!?

I need to buy a gift for my ex-girlfriend. I still care a lot about her, and I want to get her something cool/nice without it having romantic implications. It also needs to be relatively inexpensive, since I'm on a budget. She's a freshman at college, a mix of girly and butch, very invested in art and music (she's always doodling and is studying to be an art teacher). She plays guitar, her fav color is blue. Loves cute things (but what girl doesn't?). I want to get something that she'll use and can't be taken with a deeper meaning--- just something that says, "friends". any ideas? please help me, i'm at a total loss :(