How can I dress more flatteringly for my body type?

I'm going into 9th grade this year and I'm having a little trouble choosing clothes that fit properly and flatter me. I am pretty tall, with a small bust, my hips are really high up on my body, and my 's small too.. I'm not complaining, but it's difficult sometimes when half the pants you try on make it look like you have a muffin top when it's really just bony hips.. I can't wear flowy dresses, like the ones that are really popular now with the fall patterns. I can't wear rompers, either.. Any suggestions? Thank you!