Checking in on line when possible, and flying first-class and/or having high status can shoot you quickly through security.

Unless you are in international first or biz, luggage is sort of a Catch 22--if you take a carry-on you have to board early enough to find a space to stow it, but if you check you have to be at the airport at least 30 minutes before the flight and wait at baggage claim for your luggage to show up (or not).

Personally, I am happier getting on board first, stowing my carry-on and relaxing with a Bloody Mary. This is weird. I never drink Bloody Marys any other time, but almost always order one before take off, then everyone else in first-class usually follows suit. Guess that is my flying tradition.