An antique mall is a building full of separate booths, each run by a different dealer, usually under one roof and one checkout. The format rewards a little strategy, because no two booths are alike and there is far more to see than you can take in at a glance.
Walk the whole mall once before you buy anything. It is tempting to grab the first good find, but a second dealer may have a better example of the same item at a better price. A quick lap, with notes on your phone about what you saw and where, helps you compare.
Pay attention to the booth, not just the item. Dealers specialize, and a booth full of well-organized mid-century pieces or carefully labeled glassware tells you the dealer knows the material. Messy booths can hold bargains, but they take more digging.
Look at the tags. Most malls use tags that show a booth number, a price, and sometimes a note about condition or a discount. Many malls allow dealers to set their own discount, often shown as a percentage off, and some will take a reasonable offer at the register.
Ask about the return policy and about holding items. Since the mall handles the sale on behalf of many dealers, rules vary from place to place, and it is easier to ask before you pay than after.
Go more than once. Dealers restock constantly, and a mall that looked picked over on one visit can have new inventory a few weeks later. Regulars often say that the best finds come from visiting often rather than from spending a whole day in one visit.