depending on where you are to/from.. its a good idea to make sure you fly into/near the port a day in advance. flights gets delayed, you can't afford to miss your boarding.
You have to attend the safety drill thing they do.. they will hunt you down
Drop the kids off at the kid zone areas and leave them there. Pick them up for dinner or special events, don't feel bad, they will have too much fun and won't think twice you are just leaving them alone.
Get the photo package that includes unlimited photos, and get your pic taken with everyone you can find. Well worth it, as the individual photos are expensive. Look up your cruise for any special nights they might have. There are dress up nights, pirate nights.. things like that.
Meals.. if you want two entree's, you just have to ask.. same for appetizers. If you see something you like, ask for it.
Meals, meals, meals... forget about any diets. Free ice cream/pizza stations.. great buffets.
They have a drink of the day which cost's less than the the other drinks, take advantage. Banna Cariba drink.. we were sad when the day was over
Attend all the adults shows that interest you.
Excursions, in my opinion were a waste of money. Stay on the boat and enjoy the piece and quiet. Watch out for the jewelry show, they will talk about how to get around the port and all the shops, and about how much you will "save".. Don't fall for the Tanzanite pitches. Go to the places they suggest, get your free stuff and get out. Some will offer free beer, wine, that was a plus.
The doors are metal, take some magnets to dress up your door. We printed Disney character faces that fit over the door port hole.