i just started a job at the mall near my house. Im not the most experience guy in the world but i have done a few approaches at the mall cause its the best place ive found to meet single girls.
Heres what i do: i first and foremost go to look for somthing i.e. i have a reason for going to the mall. then if i see a girl who i think id like, try to make eye contact and if you get a smile or solid eye contact back, youre in, go over start the conversation and make your intentions clear. I've noticed that alot of times girls are there to meet guys too, and somtimes they will actually follow you around a bit.
For instance earlier this summer i had a full arm cast (which girls love) and i saw 2 girls ahead of me, who from the back looked good, so i tried to catch up to them. Well they went into a store and I got distracted by a sports store nearby and started looking at tickets to concerts and then at hats. No more than a minute and a half passed before they both walked in and stood basically right next to me. The hotter one says really loud
"I hope they have white sox hats here" to which i was like "im sure they do its a sports store" in a really smart ass tone. After a little pause the other one was like "OHHH can i sign your cast?!" which was amazing cause I had been joking with my friends all week that I would only let a girl sign my cast if she put her number so i pulled out the "Only if you put your numbers" in the smoothest tone i have. They both oblidged and asked for a marker, i told them theyd have to go find one which they did and I got 2 numbers out of the deal. It was obvious they were attracted to me, which helps a ton at the beggining.
The other and most fun way I do this is to go to the mall with a couple buds (a group of 3 or more) and make it a game. My friends and I made our game out of it like this:
Basically you rotate and the other members of the group pick a girl for one guy. He can veto it if shes too young/old/ugly within reason but once a girl is selected he has to approach her. We then take points. If he makes contact he gets 3 points. If he continues to hold a conversation he gets another 2 points. If he gets any kino in its another point and if he gets a number he gets 5 more. Every 10 points one guy gets, everyone else in the group has to take a shot later that night. If you chicken out, you automatically get a shot. (my friends and I dont drink so we do shots of syrup because well nobody wants to down syrup
)
But basically its just like Distant Light said, theres nothing much special about it than other approaches. The biggest problem I had was I made a huge deal about approaching (and still kinda do, like I said im no Pro). As for lines, I cant help you whole lot with that. Personally I would only use canned lines as a crutch, otherwise you'll become dependent on them and never grow. Look for context thing you can use. For instance if a girl is with her mom, wait until shes a good deal away from mommy and walk over and say "aww thats sooo cute that your mom still picks out you clothes!" (always always ALWAYS jokingly) That will break the ice immediately especially because most girls pride themselves with their sense of fashion. If you want, PM me with every situation you can think of that you commonly see girls at in the mall and I can try to help you come up with ice breakers for them.
Good luck bro!