This is more of a moving tip, but since I sold all my stuff and left my house, it’s a travel tip too =)

Change your address on all your accounts, especially bank accounts. Address changes with the USPS only go for 1 year and then they stop forwarding.

DELETE your old address from everywhere you can think of, particularly places that save multiple addresses like Amazon.com and eBay/Paypal. I had an item that I thought of at the last minute shipped from Amazon to my Austin, TX address (where I left) instead of my Springfield, IL one. Luckily it was only a $10 item.