Thank you for your hard work cabin P/A
As a no 1 on the last sector I always say "Cabin crew thank you and prepare your doors for arrival." Alot of crew have commented on how it makes them feel appreciated and alot of passengers have commented on how it looks good on an the airline to have the Senior thanking the crew for their work as it shows they are appreciated even when the flight has been especially difficult or hard. I and alot of crew don't think it's tacky but shows good team work and appreciated staff.