I have to fly for work fairly often. It is not a pleasant experience at all. If you have to fly, here are my tips (learned the hard way):
Always go through the body scanner. Requesting to go through the metal detector will definitely be accompanied by a very thorough pat-down.
Don't ask any questions. Do as you are told. And above all else: no joking, no sarcasm, no insults. Don't give them the old "suspicion" justification, which in my case led to a private back room strip search with 6 people getting a free show. And my strip search was complete with me having to bend over and spread my cheeks (and not the cheeks on my face).
Have your shoes off and laptop/tablet out of your bag before you get to the scanner. It annoys the TSA turds to have to wait 2 seconds, and pisses them off even more if they have to tell you to do something that they think everyone should already know.
Wear nice clothing, preferably business attire. If you have a beard, trim it up nice and tidy before your flight. I have found that if my beard is a bit shaggy or I wear some beat ups clothes, I seem to get more "random searches."
As for banned items, if in doubt, don't take it. Any time they confiscate something, you are more likely to be a suspect. They say you can have liquids 3 ounces or less (shampoo, toothpaste, etc.), but even if it is a 3 ounce travel size, they can judge that it is over-filled and confiscate it, so I recommend emptying a little bit out so that it is not full.
And lastly, don't run. Even if you think you might miss your flight ( which was the reason I had to learn this one the hard way). I was tackled and forced to put my face on the floor (they were very specific about me having to keep my face in contact with the ground), put in handcuffs, and taken to a back room for some serious questioning. I was apparently warned first, but I heard nothing. And I still missed my flight.
Flying sucks donkey dong. Avoid if at all possible. If you must fly, try to look respectable, and keep your head down and mouth shut.
And never ever say "this Cinnabon is the bomb!"
_________________
"The surest way to corrupt a youth is to instruct him to hold in higher esteem those who think alike than those who think differently" -Nietzsche