Plant your feet in front of them and say, "Hi, you have a great look. I'm a photographer and I am always on the look out for models, if you'd be interested please give me a call", then hand them your card, and be done with it. Do not ask them for their phone number, name or anything else. Be professional and be polite, and remember that there are a lot of creeps out there so don't be pushy. You could also have a few work samples ready if THEY pursue the conversation further. Make sure your card has your web site address on it [you do have a site, right?] so that they can see additional work samples.(posted 8826 days ago)If youre lucky, you will get about a 75% success rate.
Good Luck!