•  Especially for men - carry an (empty) clear ziplock bag in your pocket. When emptying pockets of coins, keys, wallet, cellphones, wrist-watch, rings, etc for the X-ray - dump all into the ziplock bag. Eliminates standing there at other end of the X-ray fishing coins and other small items out of the little provided buckets/bins - just grab your zip-lock bag out of the bucket and off you go. (ed. - I might add, remove your belt before the security checkpoint and stow it in an outer pocket of your carryon or inside your personal bag.)
  

• Don’t assume that other countries follow the U.S. standard for passenger screening, like carrying liquids 4 oz or smaller  (ed. - 3 ounces actually) bottles packaged in ziploc. They chucked mine in the trash in Berlin’s airport, saying they have their own standards for protecting their planes. They also gave every passenger a good frisking, which TSA agents have told me in this country they are politically unable to do…

• Let the people that have the max size allowed carry on bag put their bag in the above bin before you try to squeeze by them in the aisle. If you want to get on the plane before me, get to the airport earlier…My flights are less then an hour, I don’t check bags because once I waited longer for my bag then my entire flight.