Why cant i get a guy?

okay so i think personally i give great advise for relationships and all of my friends always ask me why i dont have a boyfriend, i ask myself that too, i mean i am a boy crazed teenager and i flirt a lot, (i think) anyways, people say im way to picky but i dont think so, as long as they dont smoke do drugs and have a good personality i will go for them, but it seems that the only guys that end up liking me are the ones that are desperate and ask out anyone, i have a low self esteem but i never show it, people tell me im pretty i dont always believe it but back to the subject, does anyone think im too picky, i tend to go for the skaters. i like muscle but only a little. most is a four pack. they have to like music. lol thats honestly all i can think of.