Perhaps the best advice is to sign up (now!) for TSA Precheck (https://www.tsa.gov/tsa-precheck/apply) or Global Entry (https://www.cbp.gov/travel/trusted-traveler-programs/global-entry/how-apply). I prefer Global Entry because it includes Precheck and it's good for 5 years for a $100 fee. Some premium credit cards, such as the Amex Platinum Card, reimburse the fee.
The only problem with Precheck is that at some airports the special lines are only open for a few hours a day, again because of staffing shortages. But not only are the lines much shorter than regular TSA lines, you don’t have to take out your laptop and liquids, and you can leave your shoes and light jacket on.
Another hack: buy priority access to TSA lines such as JetBlue's "even more speed" (http://www.jetblue.com/flying-on-jetblue/even-more/) — which gives you expedited lines through TSA. United has a similar program called Premier Access, which starts at $15. Delta calls it "Sky Priority" and it's available at select airports.
Fly from less busy airports. If you live on Long Island, fly from Islip rather than from JFK, for example. Long Beach usually has shorter lines than Los Angeles International Airport, and so on.
Try to fly on a Tuesday or Wednesday when airports are less busy. Some times of the day (such as midday) are slower than during the morning and evening rush, so lines should be shorter.
Or if you really want to make your plane on time and you fly Delta, their VIP Select Service is offered at LAX, JFK, San Francisco, LaGuardia, and Atlanta. For $250 on top of any Delta fare you get escorted to the front of the TSA line and even get a transfer between flights via a private car service on the tarmac plus other VIP perks such as Skyclub lounge access. American has a similar program but it’s only available to business and first class passengers.
(George Hobica is founder of the low-airfare listing website Airfarewatchdog.com.)