LOL, i have the same problem and i decided to do someting about it. Approaching her is enough, that will give a sign that you are interested and ready to work for it. Ask her her name, or some other cheezy lines (it does work). Then suggest hooking up (name changing,phone numbers) and voila. Call her the next day and see how things turn out.
I do have to point that it never really hit off after a few dates, but i guess you have keep at it until it clicks...Sigh, so tiresome.