Every Christmas I generate a new public key for the year ahead, and sign it with my master key and the outgoing key:
-----BEGIN PGP PUBLIC KEY BLOCK----- Version: GnuPG v1.4.8 (Darwin) mQGiBElSWN0RBADNPmjI6b01Rk6mLGUTu8bsxsmLQ+Fx06UqUO7RUoCpwGw+hroC 50RiDjkm1AxnCSdvw3g+4l+gZ7mtBE+lPy1oRi4iFPHxRoTTGY7hPV1rpHWq8PT3 ZV3DqPvuPkAj9IEVgq4K2f5BOXOd7eWBjaGHV0aUPZ32hy/iqhUUJrE57wCgxPo8 lzOr+pkhCAnDfVynamN6AtUD/1WBsCJiV9GbdUOSBiU+rLBL0r/T9roPVSXCTQen rW3rxi4th4kzVyCwQaF92jPCZP4H7pVcyTgvGvlBMhcflcQVd3xopW9AT6yMNkoD Zbb93kgLewNuOWSSyLSzzcJ0YF6mDMTsx/HH0jixUNC6YF+bmFyE3E/5A7RwZLLv KV2HBACLZa9UJQnjwgJpgjFRiWwE+sIWlf7MDrL2PWGUVY+M1VydGagUeLfM39wc MPMQYriKupS3uTfF9w9s7IFr9+NReTkxbws9WXXlbuqGexMok3smQw7iGNb5np9g C2HRkjf8ca/FKb2PqNhQZk3qr/9X7HliA0hqq4+tWNWJdhmH9bQ1TWFyZWsgSXNh bHNraSAoMjAwOSBHZW5lcmFsIFVzZSkgPHBncGtleS4yMDA5QG1hei5udT6IZgQT EQIAJgUCSVJY3QIbAwUJAjg2gAYLCQgHAwIEFQIIAwQWAgMBAh4BAheAAAoJEGar 7Aup8816VTwAn36pKRzPGkFzJZ2UnlVBdoaLZ3cuAKCK1OJTgcR6GC4gSUmjttVw 13KwaohGBBARAgAGBQJJUlmyAAoJEInQvmcIA+ginkQAoKiCkBNtZBl8XpXJy8Ex 7xnGOYftAJ0YOd8Ui2LcoHppohdB1vmlIW/whIhGBBARAgAGBQJJUlmlAAoJED/r I3KctEd7iGIAoJ1YMYHmMk/wGFIoB7n304+9KyeYAJ0UNuctEkvNQFDlfm584ue4 u7lvi7kCDQRJUljdEAgAiLcCAf75gwPd8jxWCWDiX7RgLO/DHm2HhVumV8yT1+rT 6Yqa2k3jb+TeRmI9+gQYhmOwyVyy/nls5RlaqCEWpHgBpJzCQWaM4qbZ5BR5jy8W Dcc3gHXUNx+H27ecrfP1H5vxrC5URVy0peDHZYvsaUiHEu+ICGGL5h18ZaZNlpo7 ZLkcHFT7dLIV4NnMl1ezlbUtOkfe0QzmHzI4LiOAVlPjUmHrWk0pssLUJzGX8TTg Rif9kNJqe6YxivFN4nuLxpegqUSJYCNy5wXNhIl5vZMdbs9Dlp+BpIoBvrAh48kf TMQJ3GhdbPUPbfxxz2hDK8jPSmwcd7t1r4cA4nlGvwADBQf/SdllPE/CNzpR5bKC EU8Cn4Jg6Y9ZBUQDD0BtVwA6qZ1HGADjOqvYaBlS43aCzhBFHcUtyRZdDrZDIwAx uCrPdp/roHH4Za6JthoCeShmnFfeC65ZiIEhfvFQg3GIid2+IFunKOQf4RqerTp+ NcTzBuFXMBrodPd9AnE8czrgNDpQxPMPkGqSpXvQr9AYcp0YPz/eL3e5YSm8BOQi Ss1Ds7u7Lp4QTM2XqAk1KWD8zSIsm5J7VYVmPUuG/Th/eWPW6FAqSkTTs4UL+jsv LTsGBfyf4u1IkfRPwNne3Wg+vJM4VaPUh/rYEvHAhkPIb3VjpHTWi/jVCGEppEv1 v4sOmohPBBgRAgAPBQJJUljdAhsMBQkCODaAAAoJEGar7Aup8816450AoKmQQ1AT c8efm0Cy6R7X0YRSQCyuAJ4uvfV6K4RCDqrEf8vhOu0ZJXjb3w== =gqPO -----END PGP PUBLIC KEY BLOCK-----