in my van I use a largish plastic mixing bowl for my washing up bowl... it has a small base, angled sloping sides and holds less than half the water of a traditional bowl - I also use the sponge way of washing up too...
another slobby way to not use too many resources is to eat food out of the receptacle you cooked it in
Absolutely, this actually dictates my choice of meals - if wilding and conserving water then dinner must only require more than one pan to cook it eg omelette, stir fry, all in stew etc. I like doing omelettes best as I invested in a good quality non stick smallish frying pan which makes the perfect single person sized omelette and best of all, it doesn't need washing afterwards, just a wipe with kitchen roll.
I also used to use a large salad bowl for washing up for same reason, but changed to a small washing up bowl (surprisingly considerable extra water needed) because the dirty pans, mug, occasional plate etc wouldn't fit in it when driving, so that the dirty crockery is neatly hidden out of sight underneath the draining board, which sits on top of the sink when not in use.
A small pump action garden spray (mine is 1.5L, cost about £2 in B&M Bargains or somewhere similar) is brilliant for rinsing excess food or soap off crockery when washing up, and also useful for all kinds of other things eg cleaning muddy boots, dirty dogs, windscreen etc. I haven't tried it yet but I'm thinking it would be good for washing hair with warm water.
Without going into too much detail, Ladies - panty liners.
I have a plastic rectangular food storage container which is big enough to comfortably fit my feet into, as I tend to wear walking sandals all summer, and hate going to bed with dirty feet, this is one of my luxuries if I have sufficient water and gas. Otherwise, yes.... wet wipes...
Half a dozen black waterbottles on the dashboard and 3 flasks means that so long as I don't forget, on sunny days, by lunchtime I have several litres of sometimes very hot water to save in flasks for washing or washing up at night.
I have 2 x 5l water containers marked "Dogs" as people seem to be more amenable to giving you water if it's for dogs, than if it's for you.
Nails kept short, nailbrush and mini bottle of liquid soap carried in handbag and I make a beeline for public toilets whenever spotted as I hate dirty fingernails.
Most motorway service stations now have showers in the toilets.
I have a small notebook and couple of pens in cab in which I have noted important info - eg
insurance details, height, length and width of van, breakdown cover details, exact model/mark number of my van, chassis number, GP contact details, Vet contact details, friends telephone numbers, prescription details etc, and I have taken photos of this information which I keep on my phone.
In the same notebook, I have also kept a written record of all repair work done on van, so that I can check back and see how long it is since brake pads etc were changed, and can easily see what has been spent on it. Also contact details of garages, especially ones where I can stay overnight in the van.
I use the GPS Share android app to email myself the exact location of places where I stay and then mark them on a google map so that I have my own map of my overnight locations, and can add a note eg no mobile reception etc. Save as accessible offline so can always get access to it (sometimes I remember a place I've stayed before but can't remember how to get to it, or exactly where it is).
I also carry a tape measure in my handbag (thank you Ikea, I'm well stocked), for those moments when you spot something that might fit in a specific place i the van but best to measure it and check first before buying.
It's a blooming good job women can multi-task, there's just so many eventualities, possibilities, choices or circumstances we have to be prepared for.