My wife does most of the packing, so I don't really have a "must pack" list other than gadgets. Make sure you bring sufficent cables for your gadgets, and one or more approved charging devices to charge said gadgets. Especially nowadays, if the paper Navigators are gone, and who knows when they are coming back, if ever?
My better tip is a "must not pack" list, and that is clothes. You don't need nearly as many as you think.
Put as many clothes as you think you will need into your suitcase. then immediately take out 1/3 to 1/2 of those clothes and put them back into your dresser/closet/wardrobe.
When I first started cruising (we usually do 5+ day itineraries), every time I packed what I thought I would need, I always came back with 2-3 shirts and 2-3 pairs of shorts that I never put on once. Carry that across the other four people in my family, and that's a lot of unnecessary luggage.