Original artwork should be at the top of every traveller's shopping list. Unframed pieces are nearly indestructible, fit easily into suitcases, and carry fond memories for years to come. Look beyond the local marketplace for artists. A talkative shop or restaurant owner may tip you off to the location of a local studio where up-and-coming as well as more established artists show their work.
Antique boxes are widely available in a variety of materials. I search out wooden boxes with inlaid marquetry (contrasting wood in different shades of stain), shagreen and lacquered finishes.
Serving trays lie flat amid folded clothing and are always welcome gifts. Regional examples might be made of tole (hand-painted metal), wood, pewter or silver.
Antique textiles and lace can be framed or used to create decorative pillows when you get them home.
Guest towels fashioned from linen, cotton or hemp are easily transported. Vintage examples often feature embroidered details or monograms. I've spent years looking for my own initials without success, but I've presented linen guest towels to friends with their initials, and they're always greatly appreciated. A larger set can also be used as dinner napkins.
Local delicacies such as jam, pâté, cookies and tapenade can be savoured for weeks following a trip. I search for beautiful sugars wrapped in unusual packaging, infused with lavender or decorated with fanciful details, to give away as hostess gifts once I'm home. Make sure you wrap packages in heavy sealable bags in case of breakage. I once opened a suitcase only to discover that everything in it was marinated in the olive oil I'd purchased in Tuscany.
Leather-bound books, though they're quite heavy, are often priced very reasonably at flea markets, fairs and antique shops. Vintage tomes look wonderful on bookshelves and tabletops.