Regarding our travel habit in general, I'd say it's mostly what we don't do. We don't smoke, vape, gamble, or drink alcohol (cut way back years ago because it was getting too pricey, and have since stopped entirely for medical reasons). I don't often replace my cars, and I don't pay rent or a mortgage anymore. We don't eat out often, and when we do it isn't at expensive places unless we are traveling, when we splurge a little bit. We use credit cards with good points programs (not the Disney card, which I have, but only for the discounts) for just about all our spending, and are able to use the points to pay for airfare and often hotels as well. Also, we do not EVER buy souvenirs.
We consider our lives to be comfortable, but many people would look at how we live and not think so. The cars are old, the house is very small, and our wardrobes are nothing to write home about. DD goes to a public school in what is mostly a very poor district, but hers is a selective magnet school, which is excellent. (And yes, as many know, she participates in a very expensive sport. Getting into this particular public school is the tradeoff for that; if she was in private school she would not be doing this sport, as the cost would be equivalent.) Probably the most visible sign of our frugal habits is our phones. DD whines daily about how old hers is, and mine will hold only about 20 apps, but I refuse to spend more than I have to on something so easily lost or broken.