I have regularly used the butter on the paws trick. Part of the reason it helps, I think, is that they have to lick themselves to get it off, and then they continue the wash all over, and by the time they have finished that they feel calm enough for a sleep, and when they wake up the move is all but forgotten and it's time for a nice big exploration of the new surroundings.Nice reference to Pratchett, Grab! LOL
I usually keep them inside in a safe room or roaming the house for at least a day, or longer depending on how skittish they are.
My latest move meant that my older 'fraidy-cat - she's very gentle, never fights back, prefers to run and hide - was very skittish in the new yard because it is a corner block on a busier street, so the noise of cars and passing dogs, and the big dogs next door all set her quivering. Luckily there is a fence in the back yard dividing off the street-facing side block, so I could shut the gate and know that she was safe from marauding dogs, and there is lots of shrubbery and nooks and crannies for her to hide in. She adapted well, after a couple of weeks.
Another piece of advice, from the woman with the yellow lap: don't make a quick grab for them to put them in the box or nurse them on your lap during the drive. Make sure they have done their litter-box business first. Nothing like a wet lap while driving across town with one hand on the wheel, and one hand restraining a nervous puss. Made this mistake twice!
Helen