Place your important documents, such as your identification, passport, flight itinerary and cruise documents in your carry-on bag if you have to take a flight to reach the cruise ship. These documents are far too important to place in your checked luggage. If they get lost, your whole trip could be ruined.
Also keep any medications you may taking in your carry-on baggage, and take a more than enough to last for the entire cruise.
Leave room in your suitcase for souvenirs. It's likely that you'll pick up a few things at the various ports of call, so make sure that your suitcase has enough space for them. Or, if you're planning on picking up a lot of souvenirs, pack a collapsible duffel bag inside your suitcase.
Place toiletries like shampoo, lotion and toothpaste in a plastic food storage bag, so you won't have a mess in your suitcase in the event that one of the items opens up. Also, choose small, travel-size toiletries when possible to free up room in your suitcase.
Pack dressy clothes for the formal nights on the cruise. Depending on the length of the cruise, there will be one or two formal nights, where travelers are expected to dress nicely. Many men wear suits or tuxedos, but most cruise lines allow blazers with a dress shirt, dress slacks and tie. Women should wear cocktail dresses, skirt suits, or dress slacks with a fancy blouse. The general rule of thumb for formal nights on cruises is that travelers should dress as if they were attending a wedding.
Take along proper footwear for walking. Rubber-soled shoes such as sneakers are best for walking around the ship, as they have the best traction. Also, they're good for hiking excursions at various ports of call. Dress shoes are required for formal nights, and don't forget to take along some sandals or flip-flops.
Take a bathing suit and beach towel, since most cruise ships take travelers to a wide variety of sunny islands. Casual clothes, such as sundresses, shorts, tank tops and T-shirts will help keep you cool. Cotton clothing is the best for warm climates. A hat to protect your eyes and face from the sun may be useful, and some travelers may also want to take sunglasses. Sunscreen is a necessity on a cruise, especially for those with fair skin who tend to burn easily.
Pack a light jacket or sweater. It may not seem like you'll need to bundle up while on a cruise, but restaurants and some locations you stop at can be chilly, and you might get cold on those breezy nights on or near the ocean.
Take your cell phone, as well as a pair of two-way radios or "walkie talkies." It is important to be able to keep in touch with those that you are traveling with, especially in unknown territory. Make sure you're aware of roaming charges before you use your cell phone.