TripTips.

Generally speaking:

Plan flexibly, fast and flexibly, when need be. Book early (even earlier)—(especially for international flights, park reservations) and be up to speed on your rights as you go.
Select airlines wisely as possible, with attention to reputations and ratings, safety records, carrier partnerships, etc..
It’s often better, easier to travel on or around hump day, rather than weekends (more available flights, often less expensive).
Book directly with carriers, as 3^rd parties can yield poopouts at change or reimbursement time.
Get documentation ducks in a row, e.g., passport/visas, COVID-19 vaccinations, negative tests, various testing protocols, quarantine enforcement, customs regulations, etc. at destinations.
Pack with ease-of-passage in mind, regarding number and size of bags beyond basic carry-ons.
Keep track of flight status before heading out to the airport, namely for schedule changes, delays or cancellations, via carrier apps and websites.
Ideally, check in 24 hours pre flight; maybe sign up for expediting ‘trusted traveler’ programs like TSA PreCheck, Global Entry, pricier Clear, etc..
Treat harried, underpaid airport/checkpoint/airline staff employees with a measure of courtesy and consideration for quicker, more favorable outcomes.