I've chatted up women randomly at the bus stop or on the train, I dont usually make a habit of it though.
Sometimes it works good because you initiate the conversation then the girl will be a chatter box and end up doing most of the talking, sometimes though you get a shy girl who doesn't speak much either then it's real akward as you have to think of more stuff to say!
The general trick I find is to try and do it in a friendly sort of way, such 'excuse me, you wouldn't happened to have noticed whether the the 328 bus has gone by yet?'
Now this gives the girl a chance to reciprocate, if she does like you then she will probably try to make some effort to keep the conversation going, like 'no, but thats the one I'm waiting for, where are you going?'. This means she is interested and allows you to slowly find out a bit more about each other, hopefully ending with you getting a phonenumber or something by the end of it. If she isn't interested she will probably just try to end it by saying 'no, I haven't seen it' or something that like that. This at least means you can hopefully take the hint and neither party needs to feel embarassed as you were just inquiring as to whether the bus has passed yet .
to answer some of the above posts,
If you are with another group of women and it looks like you are having a good time then that sort of makes other women curious about you, it shows you aren't dangerous since there are other women happy to be close to you and it looks like you are having a good time and they want in on it, women get jealous/envious easily, so it's basically just a play on that
Further to this, if you act like you are a confident happy sort of person then people will be drawn to you. Obviously this can be a bit of a problem for an aspie, I can do this for short periods but find it too draining to keep up for longer periods most of the time. If can manage to be a funny sort of guy who can make people laugh and make them feel good with a great personality then most women find that most attractive of all. You can be rich, tall, good looking, great body, yet if you have the personality of a wet fish then the bald, short, fat bald guy will be going home with the women. Guys are mostly visually stimulated and tend to assume women are the same, but this is untrue, most (normal, sensible) women will go for personality above all else.
It's not all bad for us though, I have also found that some women are still attracted to that sort of self assurance that (some at least) aspies have. That is I dont pay much attention to trends of other silly things like that and just do what I want to do rather than what anyone else wants me to do. That sort of self determination is something NTs, especially women, crave. They are far more susceptible to peer pressure whereas we aren't and they are drawn to that because the want to be like that too.