I think a tampon case would be great! You could make it really cute, personalize it. I also think a red bracelet would be really cool.
I'm known for my PMS and really bad cramps, so my friend made me a menstration survival kit for my birthday last year. She stocked it with mini heating pads, pain killers, chocolate, instant noodles, a concealer stick, and a book of Poe's short stories. I'd add in one of those magic heating bags, some tea, and a stress ball. Collage a shoebox or something to put it in. Add a couple silk rose petals just for fun.
When the jeans you covered with you sister's genetics notes (complete with ribbon DNA) become so famous a bio teacher who doesn't teach you rants about them to all her classes and your principal comments on your craftiness.
I made myself a travel buddy for my trip to South America. The vendors in Peru quite liked him.
Here he is overlooking Machu Picchu.
I hadn't crocheted in a while before making him, and I spent a few hours undoing the inevidable mistakes of a patternless project. His ears and front legs are a little wonky, but I'm still fairly pleased.