The first important step is to decide your budget. You can economize by opting for an off season cruise, when the rates are low. Cruise charges vary frequently in course of a year. If you are patient enough and keep enquiring, you will be able to avail low prices. If you want to cruise on a truly unbelievable bargain fare, you will have to be flexible about your vacation timings as the ships drastically reduce their charges at the last moment if they are short of passengers.
Another way to save on fare is to opt for popular destinations, because the ships tend to charge more for less popular spots.
A big saving can be made if you decide stay aboard and not leave the ship at the ports of call. Still better choose a ship with no port calls.
Be sure to have your passport, visas, insurance papers and other important documents up to date. Educate yourself with the places you are likely to visit, their customs, laws and manners.
It is always a good idea to take along your own toiletries such as shampoo, toothpaste and so on. Shopping aboard the cruise ships is very costly. Remember, you are traveling in a five star hotel or resort. So you may have to pay five star prices even for ordinary items.
Also carry some wrinkle free clothes so that you do not need to iron them frequently. Pack a few formal dresses which may be required at special dinner or other events.
Above all pack some elementary medicines for simple problems like coughs, colds and fevers besides some other home remedies like ginger capsules to avoid sea sickness.