On SQ, it is the captain or first officer who announces to the crew:
"Cabin Crew please select doors to automatic" just at the beginning of pushback.
"Cabin Crew please disarm doors" just as the aircraft is taxiing to the terminal.
Cabin crew will always cross check with each other by giving the thumbs up.
Before take off and landing, the Captain or First officer will also make this announcement:
"Cabin crew to take off stations please" just minutes before the aircraft arrives at the take off holding area.
"Cabin crew to your landing stations"... usually about a min or so after wheels down.
I have sort of memorized their announcements by heart.
There's always a better way to fly...