How to change the type of guys I look for?

im in high school right now, and typically i have crushes on the guys that go after the popular girls. I really want to start being more interested in guys who have better personalities and are much more genuine, but are more reserved or shy or....ya know...not as popular per se. I'm short, a little chubby but not very, and i have a girly, earthy type of style(if any of those things make a difference). I really want to start crushing on better guys, so please help :) how do I find a good, genuine, but maybe more reserved guy? thanks so much