RCI suggests $3.50 per person per day for cabin steward. Same for your dining room waiter. For assistant waiter, $2.00 per person per day. Head waiter - tip at your discretion, depending on what service he provides. Tips are automatically added to your bar bill (15%).
If your cabin steward or waiter or assistant waiter provide service you would consider "above and beyond", then give them more that the guidelines suggest. If you have room service, then tip the person a couple of $ when they bring the food.
Serenade of the Seas b2b January 2016
Tips are only automatically added to your account if you request that it be done. They will give you a form to fill out to do this. If you do not-they are NOT automatically added. If you do the auto-tip, you'll get vouchers w/your tip envelopes so you can deliver to the appropriate staff. If you don't auto tip, then you'll get the envelopes and can distribute cash. The only tips that are automatically added are to drink tickets-15% (soft drinks, adult beverages, bottles/glasses of wine,etc).