Probably the best thing I ever did to get random people to talk to me was growing a big curly handlebar moustache, now complimented with a long bushy beard.
My fashion choices also tend to make me stand out a bit- brightly colored Hawaiian shirts in the warmer months (I have one with pictures of the dog breed I have on it, that gets a lot of people approaching me,) occasionally a kilt (people love to ask about the kilt) interesting sunglasses, hats (used to wear a bowler occasionally, I'm less of a fan of it these days, panama hat in the summer, etc.)
Clothing and style choices are a little tricky. There's kind of a fine line between wearing something interesting that makes people want to talk to you and coming across as a fedora-wearing neckbeard who's trying too hard. Those choices have to look good on you, you have to like them and give off a bit of confidence while wearing them, and it has to be something that will catch the attention of the kind of person you want to attract.
And most importantly, you need to be able to carry a conversation from there. That's the hard part.
Having some story or a joke at the ready is a pretty good crutch to kind of get yourself over that last part. For example my go-to when people come up to me to compliment my beard/moustache is to joke that "I grew it myself" which is usually good for a chuckle, and then the ice is broken, and you can kind of try to steer the conversation from there.
I've had a lot of fun conversations with strangers and made a few friends along the way. I never personally had much luck turning that into a romantic relationship, but that was also never something I actively pursued much in general, I just kind of let things go from there and through friends who I met that way I eventually met my wife.