It can be easy to buy souvenirs for yourself of others if you collect specific trinkets such as t-shirts, bottle openers, magnets, etc. However, many people do not have collectibles and yet we want to remember the trip.
Consider buying something that you will regularly use, and it will remind you of the trip every trip you use or wear it. For example, buy jewelry native to your destination, perfume or soap that reminds you of a local scent, or a dress/shirt that will remind you of the trip.
Lead. Travel. Pray. 