Stop suddenly and fart.
Pee on their feet.
Yes, firstly, confirm if this person has bad intentions, if so, stop, wave him/her forward, slap and kick hard!
I'd run as fast as I could! Yes, I am talking about the crazy/ hot scale. You see according the the scale a girl is allowed to be crazy, as long as she is equally hot. Normally I'd take my chances, but hey this girl is following you and there's no way you could tell what she's hiding behind her back! You'd better call the police!
usually if i feel someone is following me(actually could be not)i will slow down the pace as slow as i can and turn back to pretend i'm looking for sth or waiting for someone ,and this pretending have to be covered properly by cautious observe to achieve the conclusion.
but if it's a back from late night party, i will not do that,instead I run...
Whoa, Tina..Seems to me you've got some IRL experience with stalkers.