

Get a dog, or a child; they’re chick-magnets. Even if not your own. Maybe you could take a nephew/niece/whatever to the playground once a week? Walk the neighbour’s dog for a few blocks? As someone else said, once there’s a prop, they’re not approaching you directly, they’re interacting with a common interest, and that’s a good way to meet people.
“Not at this address - return to sender” doesn’t do much, but “Deceased - return to sender” always works for me. Hopefully someone at the bank/sender flags the account and makes it the account holder’s problem.
(Don’t use sticky notes, they’ll fall off in the mail. Use a black permanent marker and write as big as possible so that they can’t “accidentally” miss your note. Cross out any barcodes or other markings that the post office adds so that it won’t automatically be re-sent to you, the machines will reject it and it will be manually routed back to the sender)