Find a window when everyone is calm and in great moods. Ignore it. Go instead when everyone is starting to get a little irritable with each other. Shop with all the children. Loud ones. Ones who don't listen. Ones who love to antagonize their siblings. Ones who run in the opposite direction to where the rest of you are heading.
Go with a list. Or don't. It doesn't matter, you will buy at least one item you didn't really need and something else will be forgotten. Get almost everything on the list apart from one item that you saw in the first shop you went to that is now on the other side of the mall. You didn't buy it at the time because you thought it would definitely/almost certainly/may be/wasn't on sale in another shop. Make sure all of you are fist-gnawingly hungry and wearing jandals that are about to break. Stop to look in a shop window at a dress that would have fit you in 1994. Listen to the deafening sounds of the mall music. It sounds remarkably like Mum, Mum, Mumma, Muuuum Smiggle.
Make it especially fun by shopping as closely as possible to lunchtime so you can wade through the mall and be tormented by the smell of kebabs. Always have prearranged plans set for the afternoon in the back of your mind just to keep those agitation levels on high. You don't have time to stop and eat.
Pop into Kmart for just one thing. Come out with a trolley-full. Be secretly glad for Kmart. Extra points given if you find a trolley without a wonky wheel. Go through the self-service checkout. Individually. Confuse the machine and force a real live store assistant to approach you to fix it but he may as well be a robot because he won't smile or talk to you at all. Do this with every other scanned item in your trolley and watch the queue of impatient people behind you grow, just for fun. Reminisce about the time that you were like the woman at the terminal beside you with children younger than yours who do the unthinkable and just let her use the machine uninterrupted. Reminisce about the time you used to do everything uninterrupted. Count you still have the same number of children as when you entered the store and doublecheck that they are all still wearing their own shoes.
Debate whether it is safe to go up the escalator with a haphazardly-stacked trolley. Decide that though it would be kind of fun to see what would happen, it's better to use the lifts and then play a game of Work Out Where They Are. Give up looking for the lifts and hike up three stories using the disability ramp with at least one of your children trailing behind and crying on the level just below you. Resist the urge to line up your trolley with the wonky wheel at the top of the disability access ramp and let it go on them all. Let them catch up. Warn them that if their behaviour continues, they're getting bundled into the car and going home. Definitely no Smiggle. Follow through. Feel triumphant at their forlorn faces. Then feel really guilty. Buy yourself an ice-cream on the way home to cheer yourself up and eat it in front of them. Feel guilty about that too and give them a couple of bites. Icecream fixes everything.