Too many times, men approach with the mindset to get her number or to sleep with her. This mindset stiffens creativity and prevents the man from coming up with new ideas.
Imagine if a man approaches another man with the intent to get his number and become best friends. That would simply be creepy.
Instead, the mindset you should take on is to play. That's it. The purpose for you to approach is to play, flirt, enjoy the interaction and togetherness of another person.
Going with this mindset, you may not want her number if she does not qualify. She does not qualify if she does not play along or respond in a positive manner.
As well, because you are just playing, it is okay to smile, don't be so serious and it is okay to say silly things like "Should I get a tattoo?"
So next time, you see a stranger, don't keep your distance because strangers don't like to talk to strangers. Don't worry what the stranger thinks of you. Better to have her think of you than not know you even exist. If she thinks your friendly attitude is wrong, then maybe she is uptight. Everybody starts off as strangers. Uptight people will never get to know anybody.