All gratuities are taken care of at the end of your sail.
You won't have to worry about tipping your stateroom attendant or dining room staff after every turn down or meal. You'll be given gratuity envelopes and comment cards on the very last day you're on board. And be generous! They provide excellent service to you and your family all week long. If you order room service, however, you should give whoever brought your food a small tip since he or she isn't part of your assigned rotation.