I did a lot of mall game over the year or so that I devoted seriously to this activity. I got two dates out of it that I remember, although those went no further. Both super cute Russian ladies as it happens, I guess the stereotype that they enjoy shopping is accurate!
The food court environment in American malls (distasteful as it may be from both a gastronomic and atmospheric point of view) is practically made for the "seated approach"; you can also wander through several times casing the joint, as it were, without drawing particular attention, due to the typical activity level in these surroundings. Once you've settled on your target(s), a "May I sit here?" is very natural in this casual, high-traffic environment.
FR: CrimeanKitten
On-the-go approaches akin to a street-stop work great here too, and make a nice substitute to outdoor daygame when the weather is too hot, too cold, too rainy, or otherwise unsuitable. Scoping out a nearby coffeeshop in advance is a good thing, and a decent-sized mall normally has more than one appropriate venue for an insta-date... in my case I kept this short, took advantage of an extra 10-15 minutes in a more relaxed setting to build rapport, before exchanging phone numbers and setting up a "true" date.
FR: WillowyCutie
It was fun to go back and look up these, hope this helps, I love this forum.