Well, having an ectormorphic genetic structure is tough. Your metabolism is out of the roof. If you want to build up a good physique, it's going to take an insane number of calories:

Bodybuilding.com - Bulking 101: The Ectomorph!

Also, there are supplements and stuff to try that can help you. These include tribulus terrestrous (sp?) and ZMA taken at bed time. (Makes you sleep like a baby by the way.) Nitric Oxide and others will help as well. Back in my day prohormones were legal, but since then they've been made illegal. Also consider a more powerlifting style workout as opposed to bodybuilding. You don't want to be sculpting, you want to eat 7000 calories a day and move huge weight to get it going.

Shave your head. Chicks dig a shaved head ... between their legs. Seriously. A little goatee will top that off ... it tickles.

Most of all ... and this is of the utmost importance ...

Be a gentleman. Don't become some superficial jerk only focused on his appearance. You can do those things to make yourself more self confident and feel better about yourself, but arrogance only works on bar flies. If you want to develop a good and loving relationship, remain humble, confident and stay a gentlemen.