Teen Girl Birthday Ideas?

Heyy so I'm going to be throwing my 15th birthday party in March and it can't that big because my sweet 16 is next year. Last year I slept over at a hotel with 10 friends but this year I'm doing something with only 3 other people and it cant be like a hotel. I'm really girly and we will probably have a sleepover too. I was thinking spa or pink but I HAVE NO IDEA!! haha please help!! Thanks so much!!