*The first day on the ship when you meet your cabin steward "make friends" hand them $5 and say thanks for having my room so nice....they'll be gold for the rest of the trip....we always tip them a little cash by hand the night before our last day as well. They work 10 hr days 7 days a week! AND with a good attitude (at least that has been our experience on RCI).
I'm not trying to start a debate about tipping but this is something I never do because from my point of view it's like suggesting that unless you give them a cash tip in advance, you won't get excellent service.
Apart from once (about 10 years ago when the room steward was just ok),I've always had very good service without the need for a tip in advance and if I feel they have made an extra special effort then I'll give them something extra as a thank you, maybe a couple of days before the end of the cruise which they still appreciate.