Holding the door open for the next person is important.
Your clothes being perfectly matched or impeccably pressed isn't. It doesn't matter if your hair is messy or just been unbrushed for the past three days. I really don't care.
You must show up on time but it isn't necessary that you address me by a title. First names are fine. Most of the time
I'll treat you like an adult if you behave like one. I'll take you seriously if you take yourself seriously. And as long as your work is in order, with regard to the rest of your life, frankly my dear, I don't give a damn.
Cutting in line is unacceptable. Walking across the street a few seconds before the pedestrian sign comes on, isn't. After all, the pedestrian does have the right of way. Heck, you can even walk across the street where there is no zebra crossing. Once in a while.
Don't push while entering the trolley. And it's impolite to speak too loudly on your phone in public. But you don't have to carry your shopping in a plastic bag. I'll understand if you carry your bare merchandise in your hands because you care about the environment. In fact, it'll probably make me respect you more.
Don't burp at the table. But it's OK to slurp your drink loudly. Seriously. I'll just think that you're really enjoying it :) As for that Sloppy Joe, go ahead and dribble. The ketchup stains only add character to that T-shirt.
It's OK to leave your unmade bed in the morning. Just make sure the volume of your television doesn't bother your neighbour.
Learn to let the little things go. And know what the bigger issues are that are worth holding on to.