Just back from the Miracle, it was a really nice ship and lots of fun. Have been on 3 cruises and have over-packed for them all - of course, being a woman. I have 2 boys. What are your kid's ages and maybe I can help? For starters you will need 2 formal outfits if you are going to be eating in the dining room every night. For the boys, just pack different colour shirts and ties to go with their suit or dress pants. (hubby does the same thing
) If they are young enough, they can get away with wearing black running shoes with their outfits on formal nights. Shorts are not allowed in the dining room so they will need some Khakis or zip-off pants (also double as a pair of shorts) and button up shirts or T-shirts to go with them. Running shoes are fine to wear. If you eat dinner at the buffet, no need to worry, you can wear what you want. Pack a few pairs of the bathing suit type shorts (maybe 4 pairs) (ones with the underwear in them) they can wear them for swimming and on shore excursions, mix and match with few different T-shirts ( I would take 8 - one for every day). This is a start, if you have any more questions, just ask.
P.S. I thought I really packed light for this cruise, and of course, we all came home with alot of clean clothes...
P.P.S. You can do laundry on board, they do have washing mashines and dryers, however, for me, the first 3 rules of vacation are NO COOKING, NO LAUNDRY, and NO CLEANING!!!
so, I just brought it all home.