Go to Wal Mart back in the hardware section and get a package of the little white plastic self adhesive wall hooks. They're like 3 bucks or something like that for a package of 6. Mount one or two of them on the bottom of your wingtips. The little hook part hangs down and will drag before your wingtip does. They are large enough to be effective, but not so big that they detract from the looks of the plane. They are pretty durable, easy to put on, and come off with a little heat from your heat gun. I used them on my LT40 and they worked great! This was mentioned a while back in Model Airplane News, by the way.