Your basic essentials such as everyday clothing and health and beauty supplies are a must to take with you when you are going anywhere on a cruise. Pack any prescription medicines that you use daily, just because that is not something that you can purchase over the counter when you leave your home area.
Keep in mind that there will be places along the way where you can purchase anything that you may be missing, but it will cost a lot more than what you would pay at home. Film for your camera will probably cost twice as much, and you may not get what you typically use.
Pack clothing that is mix and match, and can be used for a variety of activities. You are only allowed so much space in your luggage, so packing lighter is better. If you have some space left in your luggage, you can use it for souvenirs along the way.
There are all different types of cruises, and you want to make sure that you pack appropriately. Several cruise lines will have a formal dinner within the cruise, so you should make sure that you pack one formal outfit. Some people choose to wear a formal gown or tuxedo, but that is not necessary. Plan to wear something that you would typically wear to a nice wedding. Suit and tie for the men and an evening dress for the women are appropriate.
Don't forget your important travel documents. Depending on where you are traveling to, you will want to remember a passport, your cruise documents and any airline tickets or confirmations that you may have. You may not be able to board the ship if you do not have these items, and you should keep them with you at all times.