To OP--the standard tips are added to your account and you will get the coupons in your room. You place the coupon in the envelope and give it to the appropriate person on the last night of the cruise. You can alter the amount of the tip at Guest Services if you wish. Also, if you wish to increase a tip, you can put cash in the envelope. But if you give the CM the envelope with the coupon in it, you have tipped as expected.
In addition, any time you purchase a bar item, there is an automatic tip added--again, there is a line on the charge form where you can tip more, but it is not necessary.
Additional tips--IF you use the porters at the terminal, a tip of $1-2 per bag is standard. If you are using
DCL transportation, you will not use the porters on arrival. It is your choice whether or not you use them on disembarkation.
Room service--a tip of $1-5 is common depending on the size of the order. If you have 2 full dinners delivered, a tip of $5 may be reasonable. For a smaller delivery, $1-2.
Spa services--a tip is standard and not automatic.
Adult dining--most people add a tip on top of the surcharge. A portion of the surcharge does go to the server. You will read many opinions here about how much tip is appropriate; we usually tip $10 per person on top of the surcharge.
While this may sound like a lot, DCL is not a place where everyone has a hand out for a tip. I like the process of doing the coupons for the main positions as I don't have to think about it. This system was specifically instituted to aid people who didn't understand what is expected in the US/on DCL.