I do redirection as well. Sometimes it doesn't work, like today. DS generally calms quickly so I let him cry for a minute or two while in a quiet aisle. He was pretty mad about there being no car carts. After a couple of min I ask him if he wants a hug. At first he said no so I said I will be here looking at XYZ until he feels better. Immediately he comes to me and after a few quiet sobs we go. He's not typically bad tho. That's how we do tantrums. DD was worse and we've actually left and gone to car until she calms down. I once gritted my teeth so hard over a super bad tantrum with her and chipped a tooth. But I was determined to practice patience and not let her bait me into getting angry. So hard sometimes!
Go to a quiet aisle, let her calm down a bit then get her to look at me. If she doesn't, I gently hold her cheeks and explain what needs to happen, what I expect her to do (usually stop crying), and the reason for why we can't do/get whatever it is she wants. Usually there's a reward offered also. As in "We need to finish shopping so you need to stop crying and be a good girl so we can finish and go home and do X" (paint, have a snack, help with dinner, read a book, etc.) So far, this has worked for us. Once DH was with us and he had to take her out to the car but he has less patience than I do so I didn't even have a chance to do this method.
Basically this! I will keep shopping. I live to far away to come back another day. DS gets over it pretty quick
We have the same discipline no matter where we are. He usually gets it when you first let him know his behaviour isn't acceptable and will stop. If that doesn't happen we stop what we are doing and make sure we get his full attention (get to his eye level in front of him) and tell him what we expect him to start doing.
Re: How do you do discipline out in public?