Scratch Off Poster: depending what your traveler is into, Etsy stores have a variety of posters to show off all their travels. You can find National Park Checklists, 50 States Checklists, Country Checklists, etc.
Apple Airtags: they are a great gift idea for the international travelers or people who tend to fly with multiple layovers. By sticking these in luggage, you will be able to track wherever your bag is.
Coffee: a wonderful and personal gift could be buying coffee from a place that your traveler loves. For example, one of my favorite places in the world is Door County, so ordering from a local roastery there like Door County Coffee Company is a great reminder of my travels.