1. Check in online.
This means printing your boarding pass at home.  It will allow you to skip the check-in line if you're not checking luggage.

2. Checking luggage?  Do it curbside.
The lines are usually shorter.

3. Lessen the chance your checked luggage could get lost.
The number of bags misplaced by U.S. airlines has increased drastically since August (when the new carry-on restrictions began, forcing more people to check luggage). So make sure a card with your home address and phone number, as well as the address and phone number at your destination, is securely attached to the outside of your bag and also taped on the inside (in case the outside tag gets ripped off). Look at the destination tag that the airline agent attaches to your luggage -- the tag with the 3-digit airport code -- to make sure it's correct. Could your bag easily be confused with other people's on the baggage carousel (say it's a common-looking black suitcase)?  If so, tie a colored ribbon around the handle or otherwise mark it so that nobody at the carousel could confuse it for theirs.

4. Follow the exact rules for carrying onboard liquids, creams, gels, pastes, aerosols.
Carry them in containers no larger than 3 ounces, with all containers fitting inside 1 quart-size plastic zip-top bag. Click here for the T.S.A.'s rules.

5. Don't wrap gifts.
Wait till you're at your destination to wrap them. Otherwise they could get opened by security screeners. 

6. Wear shoes that slip on and off easily.
This speeds your passage through security.

Good luck, and Happy Thanksgiving!