RCCL now allows you to use your credit card (actually its their onboard credit card) to give out the standard tips without having to use cash...it's something like $3.50 per day to the waiter, $1.50 per day to the assistant waiter a/k/a/ the busboy...$3.50 per day to the cabin steward. You just buy a tip package for 2 and it saves a lot of cash. Of course, if your service is "above and beyond" you can give extra, which we have done in the past.
Actually, on our last cruise, we didn't eat in the dining room at all...we ate every meal in the Windjammer Cafe...and we gave out tips to the servers there.
What is your itinerary?