Christmas cards and holiday letters are spilling from the mailbox these days, so take note! Their arrival means it's time to update the address book.
Check cards and envelopes for address changes; update address books or contacts apps for those who have moved or changed telephone numbers.
Too busy? No problem! Toss envelopes into a file folder; when life slows down in January, it'll be easy to check return addresses against address book entries and update as needed.