I think that one thing a person must do, especially if you have never cruised before. Is to be sure and ask questions, now this is easier said than done, because if you do not know what to ask then you just will not ask.
When people cruise for the first time they should thoroughly read through all the information and brochures so that they have an understanding of what is happening.
As more and more people find the funds to cruise, the more you will have to think that it is becoming hard to get a fixed reservation. Rememeber when you could walk into a restaraunt and not have to wait or make reservations. Cruises ship dinners are the same. Even though many people opt to not choose a time, others do not know that it is recommended that they choose a specific time and arrange it.