<human>: Can you provide a brief overview of the text?

Hey guys! I'm 19 and I've never been in a serious relationship. I know that guys have reciprocated my interest before, but it never works out primarily due to me not knowing how to act. Also, when I'm interested in someone, they never pick up on it simply because I don't know how to express it.

For example, with the last guy I liked, I did try to take initiative. Asked him to senior prom, to the movies etc. He later told me that he never really got the "I'm interested" vibes from me because it felt like a really good friend just asking to hang out.

With the only guy I "dated" in the beginning of high school, using the term loosely, even though we did a lot of the things that couples usually do (like hold hands, cuddle, etc), it never moved beyond it and didn't last long. We're on good terms now, and he explained that during the time that we were together, it was really frustrating because I didn't seem particularly interested, even when I really really did like him.

With the guys I've met in college, even if I do find someone really attractive, we end up hanging out and tapering into friendship. While I'm perfectly fine with having platonic male friends, at the same time, I feel really worried because it seems like I'm not sending out the right social cues. 

What are somethings I can do to make it clear that I'm interested in someone, preferably in a way that's more tactful? I'd like to be able to flirt with/approach guys with the intention of something besides friendship, but should it not work out, be able to be friends anyway.
<bot>: I have a history of guys telling me that I'm terrible at expressing romantic interest. Would like to learn how to send out the appropriate social cues. Help me learn to flirt?