How can I become less intimidating?

Unfortunately your in high school, so the guys are going to me that mature yet.

That means they are thinking at a gut level (okay, so probably lower...)

This means they think that since they value a girl's looks, that that means that the prettier girls are better.

Thus, they think that the pretty girls will go to the best guys.

Then there's the other shoe, where you are not only pretty, but smart and whatnot. (As pretty on the inside as on the outside.)

You're a diamond in the rough and they all know it. And except for the jerks who don't really care about you, they think they are not worthy of you, and that someone else is.

Anyways, to start with, you may want to try dressing down. For instance, a t-shirt, jeans and no makeup. (I'm assuming you don't normally do this...)

I'm assuming you go around talk to people which helps with being approachable. (Such as saying 'Hi' to people who would not be considered in your circle.)

As for finding nice guys, you may want to keep this in mind. Nice guys will want to get to know you, and thus will 'stupidly' try to be your friend first.

With this knowledge you can do the following.

Become friends with people who you think are nice guys. (You learn whether you were right or not pretty quickly...)

Then try flirting with one that you like. (It's possible that the nice guy may not pick up on it, so you may have to become increasingly more obvious.)

That's the nice thing about guys, we seldom have a problem with taking a friendship to a relationship.

You may want to join some clubs. You said you were artsy, so try to find some club that interests you. And watch for the increased spike in male applicants to the club after you join. :P

Your friend sounds shy, lol, but however, (hypothetical situation, say you haven't introduced yourself to each other yet) I bet if you were to smile at him, make eye contact and say "hey" like you already know him a little - he wouldn't have too much of a problem being intimidated to talk to you. Ask him about that situation, see what he says. The thing is - you talking/introducing by just a little "hey" First, like you would to a friend, would bring down a lot of the intimidation to a shy guy. Because a few things could happen, he's gonna feel welcomed to talk to you, and you're gonna catch him off guard from him thinking "what if I say the wrong thing?" or something like that. And common thing to do is say "hi" back, right? lol. Or just smile, and wait for them to say "hi", see if they do. Because a smile is welcoming in itself. And then by acting kind of like you already know the person (look at things about a person and see if you can relate to them, and ask questions even, it's what I do) and by doing that you'll seem more personable and less intimidating to approach and keep a conversation going.