Get there as early as you want. Don't forget, the day you board is ythe first day of your cruise! The last day they'll feed you breakfast and throw you off! So get on board as soon as you can. They almost ALWAYS start boarding as soon as a crowd starts forming...usually about 11:30. Lunch is being served in the buffet and the pool is open. Don't pack your suit...put it in your carry on stuff...that way you can change and go to the pool regardless of when your bags arrive!
Ditto Steve. The mood and atmosphere seem to do a 360 the day you disembark. Smiles and nods disappear, you're luggage is waiting in another building for you, crew is busy readying and cleaning for the next group of passengers. You're all but history.
A'ndrea
You can either put your bags out the night before and then try and find them in the terminal the next morning...or do early disembarkation carry them off with you, but you have to do either or...you can't carry some and check some.