1) While it's fabulous you're shopping with your friend and her two children, please respect that there are other people in the store too. That means, don't block every isle the two of you lazily stroll down. It also means it's not a good idea to stop mid-isle, blocking off the entire isle and just stand there and chat like you're on the beach. Not everyone is there with their friend having a blast and being lazy. Some of us actually need to get what's on our list and get the heck outta there. We have stuff to do. Move it!
2) If you have three children under the age of 5 and one of them cannot be controlled by you or any other human being, it's probably not a good idea to take them to the store. A screaming, shrieking 2 year old wandering around while his mom keeps yelling at him and saying things like, "You better get over here or I'm leaving you." really makes the whole grocery shopping experience even less pleasant than usual. I get you may not be able to go shopping without all three kids, that's life. However, if said 2 year old can scream and throw a fit for the entire 40 minutes you're grocery shopping it's definitely past time you learn some new techniques on how to deal because your child is hell on legs.
3) If you work at the store and end up bagging groceries for someone that include 2 liter bottles of soda... it's not a good idea to put two into a single, thin plastic bag and then place it on the shelf under the shopping basket. The reason this is not a good idea is that when the poor customer pushes their cart out to their car that bag has a really good chance of slipping off the cart completely thus dumping out both 2 liter bottles of soda into the parking lot. And 2 liter bottles of soda roll pretty darn well. Said customer may not even realize what happened until she's already at her car and has people yelling, "Miss! Miss! Did you drop something?!"
I'm just saying.