Ruthlessly declutter!
Keep a box of essential items such as kettle, mugs, milk, loo roll in your car, plus bedding
Keep cleaning stuff, including hoover in you car. Don't underestimate how long cleaning takes once furniture has been moved out. We had actually hired cleaners to clean the house we were leaving but they run out of time. By then all our cleaning stuff had already been packed and was at the new house miles away. DH then had to go back to the old house and borrow our neighbours hoover/mop etc to finish the job whilst I was at the new house.
Buy enormous amounts of tea, coffee and particularly biscuits for the removal company. Ours were demanding tea every hour!
We had packers who packed everything over 2 days. In hindsight I would have preferred to pack and organise the boxes myself. Unpacking the contents was interesting. They literally pack everything and matching things (eg shoes) don't necessarily end up in the same box.
I didn't use them in the end, as we had packers, but you can buy moving house sticky labels with names of the rooms, fragile etc from Amazon/Ebay.
If you have pets, then set up a room just for them which no-one goes in on moving day.
I made up a little welcome pack of useful information for the new owners and left a bottle of wine and a cake.