I put in a water pump connected to a jerry can and pull out hose sprayer. It ended up being super simple and the whole system was around $80.
Second, an even simpler addition is a holder for the camp table. It was always a pain in the ass to move stuff to get to the table. Now it just slides into place.
Next, I wanted to improve my cooking setup. Setting up the table and pulling stuff out of bins wasn't that bad but requires a bit of shuffling. I wanted a flexible setup that was "freestanding" but could also be useful in other ways. I settled on a plywood "chuckbox" that can hang off the back of the truck or be carried to a picnic table and opened up. It can even be setup in the truck for inside cooking but I don't foresee doing that often. The box "transforms" into cook mode with the stove in place and additional wings for prep space. It holds all my cookware as well as plates, cups, etc. Although, fully loaded, its a bit unwieldy.
It's a bit hard to visualize but there is a cleat on the back of the box that hooks onto my pullout drawer, then another cleat that rests on the tailgate. That way, the tailgate supports the weight of the box. Takes less than a minute to setup.
Anyway, a few more pictures from a good summer and fall.