I sent one document per month per year, I know this may seem like a lot, but I did not want to take any chances. I sent everything I could think of like lease agreement ( I've been here for 6years), PayPal, eBay, utility bills, tax returns, bank statements, receipts from the gym, Sam's club and Costco purchase history, Sephora purchase history, AMC theater purchase history, medical records, Panera rewards card record, I provably overwhelmed the person who reviewed my file lol, I am very particular with my documents
So take a minute and think really hard what you did and what you can get.
Best wishes.