For ourselves, we purchase home decor items, cultural things of fun and beauty to hang on our walls. Also clothing: hats, shirts, wraps. And toys: stuffies, dolls, and other cozy things.
For our friends, we purchase cultural items they can enjoy in their cubicles at work. Our friends also bring us cube accessories from their vacations. Butterflies from the butterfly museum. Tiny wooden fish with wagging tail. Blue & white building replicas from Greek Isles.
We always travel with at least two expandable bags, which of course are not supposed to be expanded when we start our trip.
All of our purchases are supposed to fit in the expansion spaces of those two bags. 
We always travel also with at least two nylon bags (the kind that fold up into their own small pocket) for any add-ons we pick up along the way, at the airport, at the beach, shopping in town, or for anything else that we may suddenly find ourselves needing to carry, such as our jackets, hats, shoes.
Joan (of Jeri-n-Joan)