Our old ShopVac UltraPro 16gal is great, but when you have to pick it up to lift over an obstacle, or carry up a flight of stairs, it is not just awkward and heavy, but the miserable handle design (see third photo) makes it actually painful to carry by its handle. So I made a pad for it. 

This version is intended to be printed in flexible material such as TPU. I made the pad to fit the handle (it doesn't even need glue), but the handle is curved, and I made it to print flat. This works perfectly with flexible material. If you wanted a rigid pad printed with PLA or PETG or whatever, you'd need to redesign it.