We like to carry 6 of the 5 litre water containers from supermarkets, but they do like to shift about when driving, but I have a couple of those plastic fold up crates which when screwed to the bottom of the wardrobe keeps them safe and sound.
I use a spirit level app to level up the van, calibrate it at home, then park the Moho somewhere flat to see where it's best to put the phone in the van then once on site/layby/field you can easily see if you're out of level or not and adjust accordingly, I found this one
the most accurate.
After a fry up, clean the pan with kitchen roll before washing it up, and if you use it every day, just wash it once a week or less
Re-use any supermarket free bags as bin liners, we never threw any away, and have tons of them stashed just for the van.
When possible buy the plastic bottles or containers of sauces etc, not glass for the van, less likely to damage the work/cooker top when dropped, and they don't rattle.
Use tumblers not wine glass, they're more stable and less likely to rattle.
Invest in a good set of stack-able pans, less space taken and less rattles, we use these
We use small plastic baskets to put cooking and other smaller items in inside the lockers, so easy to find things and the support sauce bottles etc.
Height and width on the visor.
Sprayer for the loo.
Stain removers for the inevitable accident.
If you have quite high upper lockers fit a shelf to give more small item storage.
Keep loo rolls in a cupboard so they stay dry in the bathroom, don't see the point of a roll holder at all.
Make mats for the shower tray out of carpet off cuts.
Ive' done other mods, but that'll do fer noo.