We often "boondock", which means that we are not attached to any services. One of the important habits to have is water savings. We cook and eat like we are at home, so we have dishes and pots to clean. To save water during the washing process, we have taken to using plastic tubs inserted into our RV kitchen sink. See above photo.
The tubs were purchased to fit as closely as possible our built-in sinks. We keep one tub for wash, one for rinse. Using the existing wash and rinse water shortens the time we keep the faucet running.
When we are done, we empty out the soapy wash water, and clean the plastic tub we used. The rinse water tub becomes the wash for the next meal. We sized the tubs, and they hold about 1 gallon. We try to keep the amount used at that volume, if we can.
Yes, we know other boondockers who use no water at all, usually using paper plates and not cooking with any pots and pans. Your mileage will vary...
We often stay overnight at Walmart stores on long trips. We don't need special RV parks, and can just sleep in our motorhome and get going the next morning.
We have a list of Walmarts that allow overnight parking, but: where to park? We are 40 feet plus the car under tow.
We used to just drive in and try to find a spot. That is a recipe for big trouble. Nowadays, we use the Google Maps application on our phone, and turn on "satellite" view. That way, we can preview the layout of the parking lot, and prepare to drive in and use what appear to be the best spots for our RV.