1. Do not overpack
2. Dress for dinner as you would at any nice resturant, that really is the dress code.
3. Formal wear is really no longer a "have to" Suit for a guy, nice attire for the women, that really is it.
4. Most of the time you will be strolling some where, so comfortable footwear, shorts, tee shirts is the uniform that makes sense.
5. We have cruised numerous times, my wife over packs, always regrets it.
6. Transporting luggage from the time you leave your home till you get home is always a pain, and less is better. I travel extensively during the year and if you get by with 1 carryon and 1 checked bag that is the way to go.