OK MY BEST ADVISE TO YOU IS IF YOU HAVE ALLOT TO DO LEAVE EARLY .specially if he has tantrums ,have plenty of rewards such as a lolly pop or sticker to use it to keep his behavious in control .but if you child is like mine who has full tantrusm and no matter what you say they keep going this is where leaving early is handy take your child outside and sit them in any corner of the building even if at a shopping centre then either turn your back on them or look else where so you dont at least make eye contact .dont give them attention no matter how much they yell.and dont worry about what others think if they dont like it they can walk away .but if you give in to the tantrums just because your busy or in a rush thats teaching your kid its ok to behave bad .so take your time .and with disturbing customers ,most will understand specially if they have kids .or if you have a busy squedual take a friend with you cause then if your kid has a tantrum they can take him for a walk adn keep him occuipied

Hiya!  With my 3 year old, I use a very quiet but stern voice, making sure she's looking at me, and tell her that if she hits me again, she will go in to time out.  Our time out when we're in a public place is that I hold her on my lap (wherever possible) with her back to me and I basically constrict her movement, but very gently.  I don't talk or interact with her when I'm doing this either.

The other "time out" that has worked exceptionally well is when we're doing the grocery shopping she's told that if she misbehaves, she'll go in the trolley seat.

Hope this helps some and good luck!

When my kids play up in public. I ask them if they want to go to their rooms when we get home. If their bad behaviour continues. I tell them they will be going to there rooms when we get home, and I usually try to get home asap.  As soon as we get home, I put them striaght intot here rooms, for however long.

Then I go and tell them why they had to go to their rooms.  It generally works well they start to realise that if they muck up while we're out then we go home, and they have time out.