I have a routine when I work. Once I ring you up, I'll tell you your total. It is then that I will ask if you want a bag.
I usually get the bag while you are searching for your money (which you should already have out and ready, but never do).
While you are digging around for money, I will quickly bag your purchase, take your money, and everyone is happily on their way. It works so nicely.
It doesn't work, however, when I ask if you want a bag and you stand there thinking about it.
Do you really need to take 30 seconds to think about whether you want to put your shit in a bag or not? I watch everyday as some people even cock their heads to the side and crinkle up their nose trying to decide.
The problem with this is, you ruin my timing. While you are pondering life and whether you want paper or plastic, I am half bent over on my way to get you a bag and when I have to stop in this position waiting for your answer, it hurts my back, as I've said before.
And when it hurts my back I tend to purposely smash your food items as I'm eventually placing them in your precious bag.
I think I'm going to make a checklist of all the things you should have ready before you get to the register to checkout. Then for a week straight I will place them in everyone's bag like little flyers, so once they get home they can read and prepare for their next time.