I can't believe it or almost want to deny but i use to have this problem. I would take this advice though. Talk to anyone. For example: I was buying clothes and would chit chat with the cashier about these crazy prices just for me to look good in public. Chat with the average looking lady serving your food at TGI fridays or subway about "omg it's been a long day, oh really, yea me too, haha have a nice day".
Then escalate.
See a hottie shopping or... idk wtf/e just ask to help, or something random pertaining to what she's doing then once that subject you brought up is over, walk away. CAUTION!: if you do this step, and it works aka you get a good reaction... that doesn't mean your ready to drop a 20 line script on her ass. walk away. you did good for yourself by opening to them more, don't fuck your self and jump into something you "think" your ready for.
Escalate some more.
being the sets. But don't plan them. Like you said you were walking around a mall. Don't plan it, walk up on them as your walking past them or walking too them. "hey do you know where i can find X in the mall?" (sorry that is kind of broad but there are so many examples i can give it's dumb) there's a shit ton of things you can ask them if you think about it.
Gotta crawl before you can pick up numbers from HB's at the mall... let alone walk...
