They enjoy the natural touch that plants add to a home. Plants also can be pleasant to contemplate and visually enjoy. Don't forget flowering plants. What about a nice planter or dish garden. These can be very elaborate combinations of all kinds of great plants.
Florists carry balloons as well as flowers.
Consider a lovely vase arrangement with a cluster of balloons. Stuffed animals are real sentimental favorites with grown ups as well as kids. Consider a combination of stuffed animals and flowers. They are sweet and romantic. Today's flower shop carries all kinds of gift items.