Lovely teacups and a great idea to make use of the pretties. I have decided to do this with a few that I inherited --- going to use the florist clay that is waterproof to gob the cup to the saucer and then will make a snug cushion using wool roving to stuff it and probably use a bit of candle snugger wax to attach it to the cup. I think this way the cups will be usable for their original intent if desired down the road. At almost 60 I am trying to think of ways my family heirlooms might be useful as well as decorative and other people may repurpose them later. With glue I might be committing the cup to the trash bin as not everyone in the family sews.