Most banks/financial institutions will let you download pdf statements back over a period of time. Revolving accounts such as checking/savings/credit are typically a year and others may go more. I switched to paperless a while back and scanned any prior to the date I could download. I keep two folder structures, one for accounts and one for archived\accounts. The accounts I keep anything still open and moved to the accounts under archived if I close an account and just want to keep the data.
Before I moved I also cleaned up all my scrap wood/materials/computers/electronics piles, all those leftovers from small projects or items that broke and I kept for spare parts. Any furniture thats not heirloom you can sell and buy. Tools and gear I made sure to have toolboxes/bags/rolls etc that everything can be stored in to prevent small items from getting lost.