This is a great list!
1) Yep, we are some of the people with tons of luggage because...why not? It's delivered to you-- take whatever will make your trip great for you! We also dress up nightly for dinner, so that takes space. Fly Southwest and two checked bags per person are free.
2) We get a vacuum bag and take our own foam "egg crate" pad with us for the bed. It's so much more comfortable and that irritating crack between the two twin mattresses put together is magically gone. We ask the room steward to bring the vacuum cleaner the last night and vacuum the bag for packing-- it's amazing how strong those Carnival vacuums are!
3) For those that do like to use the paper Fun Times, bring a highlighter to mark your favorite events for the day.
4) Skip the shopping show and the free charm bracelet hunt!
5) Skip the debarkation talk and just watch it on the TV.
6) This may not be for everyone, but...we take some "ready to be retired" underclothes and just chunk them in the trash at the end of the week. Saves space (minimal) on the way home and eliminates taking that dirty laundry with you.
7) I've read online that eating green apples can alleviate motion sickness. I can't verify that, but there you go.
8) Use your open luggage under the bed as either a dirty clothes hamper or an extra "drawer."
9) If you have a balcony cabin, the couch has 2 huge drawers under it. Ask the room steward to remove extra blankets/pillows if they are in there.
10) Pack jewelry in a 7-day pill container.
11) Bring aerosol or pump spray Wrinkle Releaser so you can skip the ironing room.
12) Bring conditioner. The shampoo is fine/available, but I have to have my conditioner!
13) Bring your stash of hotel bottles of conditioner. The just throw away the empty ones and you have more space going home.
14) If you work out, bring powdered Gatorade. Buy one bottle on board for your first workout, then just refill it with water/powder on subsequent days.
15) Monitor your sail-n-sign account. We've found charges not ours and double charges several times. Just go to guest services and they will investigate to verify, and take care of it. We've never had an issue having charges removed that were not really ours.