It's not something that airlines or travelers like to have happen, but every now and again, instead of just being delayed, an air traveler finds themselves stranded due to a flight cancellation. It's no fun but there are a few things you can make be a part of your regular air travel routine which can help alleviate little annoyances that make a bad situation become worse.
Make sure you have essentials with you, not in checked luggage. This includes medicines, money, addresses and phone numbers, and personal care essentials. I don't wear contact lenses anymore, but when I did, I always made sure a case for my contacts and my glasses were with me. I had a few close calls where I almost didn't have cash or an ATM card, mostly in my college years, and I chose to leave from those instances rather than repeat them.
On travel days, I always wear something that I can adjust to be a bit warmer or cooler if need be. I'm not going to presume to get a blanket on a plane and then wind up freezing as we sit delayed on the tarmac. Likewise, being overheated or too cold in a terminal can make delays stretch to forever. I once spent five hours sitting in a plane on a runway watching crews de-ice the wings repeatedly, all the while being thankful I was wearing very comfortable pants. I always travel with a book I'm about to start reading, not one I'm about to finish. And on long flights or during winter months, I might just have two books with me.