We recently purchased a windshield washer with an extendible handle, similar to this:
I also keep a gallon of windshield washer fluid in the basement. When I run out, I want to be able to fill up at the next rest area.
I may get a 7' ladder to strap to the back built-in ladder for when I have those nasty love bugs off of the windshield.
A large woven plastic mat to place on the ground in front of the door. When it's time to go, sweep off the top of the mat, then fold half of the mat back so the top is together. Now sweep the half which was ground side and fold in half again. Continue the sweeping of the ground side until the mat is a manageable size to store in the basement. Hold it up while someone else sweeps that portion. Now you've got a relatively clean mat to put away.
Rather than duct tape, which is generally not pretty when removed, we carry gaffer's tape. It's a little more expensive and holds as well as duct tape, but when you remove it there is no residue behind. Three rolls from Amazon for under $30.
I have an in-line flow meter which connects to the intake of my 3-stage filter so I can monitor my water use--and know how many gallons I've run through the water filter and water softener.
I also have a Y to connect to the hose bib at the RV park. One side of that is open for a general purpose hose in case I need to wash my windshield or RV. I carry a nozzle for that hose, too. The other side of the Y has an oil-filled pressure reducer which has a Y off of it, to which I connect the hose I connected to the black water tank flush connection--I learned the hard way to use the pressure-reduced water for that when I connected to the Y closest to the hose bib and had a bit of water coming out of the fitting at the top of the holding tank. The other output of the second Y has the typical Camco 150 micron water filter on it and that goes to the flow gauge connected to the water filter.
I don't have them yet, but I'll be getting spare cables for my toad: emergency brake and 7-wire cable. When we stop at a rest area and the coach/toad are unsupervised, I'll pull the cables and safety chains to save someone else the bother of stealing them from me. I hit a set of railroad tracks coming out of Stephen C. Foster State Park in the Okefenokee Swamp a bit fast a month ago and the 7-wire became disconnected from the toad. Luckily, it didn't drag on the ground because I routed it over the tow bars. If it ever does, I want to have an immediate replacement.
I have a Garmin RV 1090 GPS unit--it takes as part of the setup the height, width, and length of the unit and only maps routes on which the coach will fit. I also went to an Escapees campground and got a four-wheel weigh. Not something one packs, but they gave me a sticker for my window with the height of the unit so I don't scrape the roof on an underpass.
I also wrangled some wires to a 12VDC power splitter (with 4 USB ports)--I'll try to post a photo, but I've had rotten luck posting photos in posts. The TPMS and Blue Ox brake controller are to the left of the head unit.
We take small fans for the bedroom, so we don't need the noisy A/C running at night when it's warm but not hot. We'll probably get a couple of quartz space heaters so we don't need to propane while we're paying for electricity in an RV park.