Our top tips have mostly been covered elsewhere, but here goes ....
Go for the largest LPG tanks you can fit.
Same for
solar panel.
Sine wave
inverter.
Add a few more USB sockets around the van.
Sacrificial wallet / laptop.
Scan all docs and store in email folders.
Have a UK address if possible: someone to scan post and email it to you, AND register with Electoral Roll ... it can affect you
insurance premiums.
Be honest with insurers about full timing ... but do get lots of quotes, as we were quoted anything between £650 and £1700.
Take more warm clothes and layers than you think you'll need.
And conversely don't pack your whole wardrobe ... you won't need it or have room for it.
Cancel all junk mail and go electronic for statements months before you set off.
Pressure cooker ... saves gas and tenderises meat. Can't recommend enough.
We have pics of family on the wall, but change glass to clear perspex.
Work out how to give your travelling partner space ... we all need it at times.