All pertinent documents regarding taxes, credit cards, investments, mortgages. Birth certificates, marriage certificates, if there are children, everything that pertains to their school and doctor records. Title to your car, boat, motorcycle and so forth.
I would open an account in my name only, start stashing money in it.
Start sorting and staging the items you want to take with you.
I am sure there is more, others will be here to add to the list.
Take care