I try to do my grocery shopping on days that both of my boys are in school which means I only have to take my 2 year old with me. It is a challenge to go shopping with more than 1 and my kids have thrown tantrums in the store with everyone staring at us. Some people look at us with understanding and you know they have been there before and others look with disapproval because either they don't have kids, have absolute angels for kids, or have babysitters to look after they kids while they shop. I have developed several rules of thumb when taking my kids shopping with me.
1. I always go at the least busiest time of day such as early on a mid-week morning. I rarely go shopping on the weekend or on the day before a statutory holiday unless I absolutely have to.
2. I try to bring a snack along so that they are not tempted to want to snack on junk they see on the shelves. I also like to bring a drink along. I find that kids get trantrums when they are hungry. It can also distract them when we get to the checkout where they see all of the candy.
3. I sometimes get the kids involved in finding groceries on the list for me. This keeps them from getting bored.
4. I will let my 4 year old push the cart for me if he asks. I help him steer it and make sure that he does not hit someone.
5. I try to limit the time I am in the store to about 30 minutes at most. This means that I have to know exactly what I want and where to find it.