Personally I like the procedures at Qantas and Jetstar. When the seatbelt signs are on, even the crew must be seated. Jetstar, even has an automated PA when the signs are turned on, which says something along the lines of
"Ladies and Gents, the fasten seatbelt signs have been switched on. Please return to your seats, and fasten your seatbelts. Cabin crew, please secure the cabin, and take your seats"
Cabin crew complete their secure for landing before the seatbelt sign is turned on.