Check Your Carry-on at the Gate
This one only works if your bag is already the approved carry-on size. If you reach the gate with your luggage plus one bag and the flight is very full, the attendants will often ask for volunteers to check baggage to free up space in the overhead bins.
Take this opportunity! They'll tag your bag, give you a receipt and your bag will be checked through to your destination, even if you have to change planes in the middle of your trip. You'll have just your purse or laptop bag with you in the cabin, which has everything you need anyway, like headphones and a book or a sleep kit.
You've probably noticed that space is at a premium in airplanes these days. We'll talk about how to get your gear into that space next.