Two areas of tips not covered above are adult dining (gratuity is included in the upcharge, but many guests add more) and the porters who you may use for luggage assistance. If you use private transportation, you'll drop your bags with the porters prior to entering the terminal (not an issue if you use
DCL transportation TO the port). After the cruise, you may choose to enlist the help of a porter in the terminal--they will take the bags thru Customs and to your car, bus, limo, shuttle, etc.) Obviously, at this point, their service is optional and many handle their own bags.
Any bar purchase will include an automatic 50% tip. This includes smoothies, specialty coffee, light up cup clip ons, etc., not just alcohol. There is a line for "additional gratuity" which you are free to add or not as you see fit. Just remember that you've already tipped 15%.