I work at a small liquor store. We generally get the same customers from day to day and it's actually a pretty relaxed retail environment.
My biggest complaint-- aside from corporate of course-- is when a customer comes to the checkout on their phone. It usually happens a few times a shift and it's always a bit awkward as company policy requires that I ask them a few questions during the transaction.
Anyway, a man that i havent seen before came to the counter for the second time that day as he forgot something the wife wanted. He was pretty upbeat and trying to make genuine conversation with other customers and coworkers. I ring him up as usual and make some small talk when his phone begins to vibrate. Then the most magical thing happens, he silences the ringer and says, "Is it alright if I take this call?" I'm blown away. Never before has a customer asked my permission before doing much of anything. I tell him to go ahead and finish the transaction like normal and he leaves with a quick thank you.
I stood there for a while after he left just thinking about what had happened. It honestly made my day a little better. Just a little courtesy can go a long way in making a retail employee's job less miserable.