The best way to avoid lines is to book travel during off peak times. For example, during March break, Pearson Airport in Toronto welcomed 130k travelers. If booking during off peak season isn’t possible, applying well in advance for a Nexus trusted traveler card allows you to bypass the main TSA line, usually. The application process can take a few months. It’s free for children, and has a modest fee for adults, 50$. Apply for US census card at the TTP, Trusted Traveler Program website. 

https://ttp.cbp.dhs.gov/?utm_source=google&utm_medium=google&utm_term=(not%20provided)&utm_content=undefined&utm_campaign=(not%20set)&gclid=undefined&dclid=undefined&GAID=1740252400.1571924483

Every person in the travel party must have a card to use the priority line, and you may have to put the numbers of the card in at bag check, or online when you book the reservation, in order for it to show up on your ticket. 

To keep everyone moving quickly through security,  have any liquids in a zip lock baggie ready to present to the agent, and make sure they conform to the volume restrictions. Have tickets and IDs ready to present, as well as phones, keys and other metal items out of pockets before moving through the metal detectors. This ensures seamless checkpoints for all.

Sneaky tricks to avoid the line up to board include always bringing your child in a stroller to the gate. You’ll get a tag for the stroller that allows you to check it right before stepping onto the plane, and often be allowed to board with or shortly after priority boarding. There are limits to this. No 9 year olds in strollers, please. Let’s be fair.

Choosing a credit card that allows priority status on the airline you travel most frequently also often allows priority boarding. My favorite is the Jet Blue card through Barclay Card. Enough miles will get you mosaic status, offering one free bag checked, priority boarding, and other perks. http://Barclaycard.us.com