What's the point of attracting the momentary attention of passing stranger? Ты don't need other people to justify your existence. If no one is looking at you, Ты won't disappear. Your not some kind of vampire that needs acknowledgement to survive.
You'd be surprised how many people notice Ты already--this I know from experience.
However, if Ты do want еще attention, and Ты don't want to do anything too drastic, wear something that's unusual for you, или style your hair a little differently. That will get others asking what's going on.