Traffic is inevitable and parking is an absolute nightmare, especially when going to popular locations. Also lines are long and if you're planning on going shopping for a long time, you must get in and out of lines as fast as possible.
2) Know where you are going.
I find it easier to shop when I have a solid plan. Know what stores you're planning on going to. It's easier and makes it less frustrating because Black Friday's already very chaotic.
3) Be patient.
Patience is key. There will be long lines and there's no use being impatient. It'll make your shopping experience less enjoyable.
4) Be kind to the salespeople.
Treat them with respect. They're human too and I really doubt they want to spend their whole time catering to an entitled customer. Don't be that way.
5) Make sure you don't take too long in the fitting rooms.
There are always long lines for fitting rooms. Don't be the jerk who takes a lot of time. It's one thing to have a lot of clothes to try on, but it's annoying when you have like one thing and you take a long time. It's common respect and don't make it worse for others.
6) Take breaks.
If you go on long shopping trips, do take breaks. Eat a snack, drink coffee. You'll be thankful later and you won't be as cranky.
7) Enjoy your experience!
It's not all about what you buy, it's also about having fun! There's no reason to make shopping unpleasant.