What I have made today, is a set of ground blocks for the Airstream stabilising jacks. Using old blocks of wood is particularly useful to help prevent direct contact between the metal foot/disk with the wet ground, in an effort to prevent rust. It also makes it a little easier to wind down the jack foot when setting up for camp.
Complete with carrying handle, so you can carry all 4 blocks at once with ease.
This only took 15 minutes to make, and a little effort goes a long way.