I’ve tried many methods to keep my long leather boots in great condition. This has involved finding ways to keep the leg of the boot from folding over on itself. By far, the best method that I have found is to cut pool noodles down to size to fit the boot.
Yes, pool noodles. Not just for the pool, these things are fantastic for keeping your boots happy.
I purchased a pack of noodles at Big W several years ago and they are still going strong. So rather than wasting money on inflatable boot shape holders and the like, try a pool noodle; they do an outstanding job in… and out of the water.