Being a "ladies man" myself, I can tell you what makes men sexy for women. I have a great amount of experience in pleasing dames and I am willing to pass on the knowledge here for those of you who are, unlike me, geeks at the art of making girls happy.
The first thing you must do is make sure you put on some nice music. I would suggest the Bee-Gees or Gary Glitter. This will do it, and if it does not, try Rick Astley. Every woman who is worth your time will love Rick Astley...'never gonna give you up...never gonna run away...etc.'
It will put them 'in the mood' if you know what I mean.
Second, ask them if they want to watch a movie. I would suggest something like 'Citizen Kane' or 'Macbeth'. These are not sexy movies, but they will give you something to discuss if she finds you boring. (Which happens to me alot.)
Finally, ask the girl in question if she wants you to take off your clothes. If she recoils in horror, then maybe you should pull out your collection of stamps and try to impress her that way. If she says 'yes!' then do it before she changes her mind.
Follow these tips and you will be just as hot as I am!
Good luck. You will need it.