A few years ago I had some work done on my house. There were 2 owners and 3 employees. The day the work was to be finished, I had laid out about 15 paintings, mostly landscapes, on stretched canvas or canvas board or canvas paper from 9x12 to 18x24". One was a seascape which I really liked, but in colors I didn't like. In the morning I told them I wanted to offer each of them a painting, my thanks for the work they did. I said, "You may not like any of it, it may not be your cup of tea, so if you don't want a piece, I understand. Come look at it now, and when you're ready to leave, come back and choose. I really appreciate what you've done." So they came in and spent several minutes looking, then went out to finish the job. They came in later and all accepted a piece, including that large, colorful seascape. I heard one fellow say, "You don't like seascapes." The other man said, "I love the colors!" Another man told me he chose his because of the theme, they have a room decorated in a similar fashion. His wife called the next day to thank me, and said they went and have it framed already. It was especially nice for me, too, to have passed those on.
Another possibility: If you (or a neighbor) is having a garage sale, set the paintings you want to go into a box marked "one of your choice, free" with each purchase. Of course, if they can't decide between two, let them take both and try them in their homes.
Two of my doctors' offices had unframed pictures hanging with price tags on them. A local cancer hospital also had paintings displayed (framed and unframed, prices attached) and other objects on counters or in glass cases-sculptures, needlework, jeweled pieces, (not jewelry) note cards, etc. On their three floors. By local artists.