1. I over packed.
I pride myself on packing light, but on my cruise I wound up not wearing about 1/3 of what I packed. During the day, shorts, tshirt and flip flops was more than enough. I packed more jeans and slacks than I needed to. I could have done just fine with one pair of jeans and one pair of slacks because my cruise was pretty casual, and during warm weather.
2. Water is EXPENSIVE!
Once onboard, if you like bottled water, expect a charge of $2.50 to $4 for ONE bottle of water. You can purchase a case of water before you board and check it in with your luggage.
3. Limited outlets
Your stateroom will likely only have two plugs, If you have an iPad, cell phone, and other gadgets to charge, bring a strip so you can charge more than two gadgets.
4. Be flexible
If you like to eat when everybody else does, expect bigger crowds. Plan your meals a little earlier or later, and you'll get more attention from the wait staff, and less chance that any special orders get messed up. We ate dinner around 6:30 pm in a dining room that was almost empty. By 7:30 when we were leaving, it was packed! A smile goes a long way. The wait staff is busy, and they serve hundreds, if not a thousand people every day. So cut them a little slack, and roll with the minor stuff. My wife is allergic to soy, so it took a little longer for them to make her something special one night...they comped us a free adult beverage and a dessert without us needing to ask....just because we were nice about the whole thing.
5. Extra charges
If you decide to play bingo, it will cost an extra $49. Beer tasting? $15. A banana split at the 24 hour snack bar? $6 A bucket of 6 beers while relaxing at the pool? $30 Internet? $100 for an hour. Extra fees shouldn't be a secret, and I'm surprised at the folks who complain about them because cruise lines have been doing this for at least two decades if not longer. When you book your cruise, you should budget for "extras", especially adult beverages.