Any general advice for VERY skinny guys?

I'm pretty sure girls aren't that into very skinny guys. I'm also very tall which doesn't help. Is there anything I can do to kind of mask this or turn it into a positive? Are slim fitting or baggy clothes better? Gaining much weight for me isn't realistic due to health issues.

EDIT: I'm close to 6'3" and am 140 pounds soaking wet. I lead a pretty casual life in a small city. I work in a very casual office environment. Jeans an sneakers are the norm so dress clothes are probably not necessary. I still try to look nice though.