Money:  Most ports of call will take U.S. dollars when purchasing goods & services abroad.  A few will require you to only use the local currency.  Changing money from one currency to another does cost something.  Depending on where you get the money changed into the currency needed could cost you dearly.  Usually the biggest problem is the homeport that your cruise will sail from.  It is a good idea to have a few dollars of the local currency that you first fly in to.  This way if you can not find a place to exchange your money, you’ll have enough local currency to eat if you get hungry or money to ride the subway, etc.   There are probably banks in your hometown that will exchange your currency for the desired currency.

Enough Spending Money: There are a few things most people do not budget for when taking a cruise.  Here is a list of a few items that you may not have planned for. 

Photos/Videos: The onboard video or photo department will be snapping pictures and shooting videos that you will want to buy.  Just put it in you budget now so it won’t drive you crazy during the cruise.   Average price per picture is $7 and $45 for a highlight video of your cruise.

Shore Excursions: A great way to see the Ports Of Call in the limited time you’ll have on your cruise is on an organized shore excursion offered by the cruise line.  You may get a better deal if you book an excursion through a private tour company prior to sailing, however problems could arise if the ship docks later than originally planned or if the company goes out of business.

Tipping:  See Tipping Below
  
Luggage:  It is a good idea to pack complete outfits in different bags instead of packing one bag full of pants, another bag full of shirts, etc.  This way if you loose a bag, you will at least have a few complete outfits to make it through a few days.  Do not over pack.  Remember that you will probably buy something to take home, so leave some room.  Perhaps put a full suitcase inside a larger suitcase or pack an empty, soft carry-on bag.  Expect your luggage to be tossed around.  Any bags that show signs of stress should not be used.  And do not pack any glass or pottery items in your luggage.  The last night of the cruise you will probably be asked to have your luggage outside your cabin door.  This is to expedite disembarking the luggage.  Remember, before putting your luggage outside your cabin door the last night of the cruise, to leave out a complete set of clothes to wear off the ship for traveling home and or anything else you will need in the morning like pills & toiletries.  After you place your luggage outside your cabin doors, you will not be able to retrieve your luggage until you exit the ship and go through customs.  This could take several hours so plan for it.   Remember to bring a carry-on.  You will need it the last morning of the cruise for any break-able items, prescription drugs, valuables and your PJ’s & toiletries.

Passport & Visa: Most places throughout the world will require you to have proper documentation, i.e.: a passport & perhaps an entry visa.  It could take you months to get the paper work needed to board a vessel.  Check with the cruise line you plan to travel with and ask them what you need to bring.

U.S. Customs: When returning to the Untied States after your cruise, you will probably have to go through United States Customs.  This can sometimes frustrate the most easy going person on the planet because it can sometimes take hours.  As you probably know, U.S. Custom Agents are trying to protect U.S. Citizens against people entering the United States with illegal or dangerous items.  So they have amazing search & seizure powers and they will use these awesome search & seizure powers whenever they feel they should.  They also use trained dogs to sniff luggage at many ports.  Depending on the number of custom agents and the number of passengers, the time involved for everyone to disembark could take a few hours.

U.S. Customs also collect money from people returning to the United States with purchases that exceed the duty free shopping limit.  You are allowed to purchase a limited amount of goods “Duty Free” or Tax Free”.  Once you go over your limit, you will have to pay a tax to U.S. Customs.  The limit may vary depending on where you are going, so check with the cruise line if you plan to buy lots of stuff.
 

Tipping:  Most service personnel onboard cruise ships make a tiny salary and generate most of their income from passenger gratuities or tips.  There are fairly standard tipping guidelines among most cruise lines.  During your cruise, the cruise director usually has what is called a disembarkation talk.  During that talk, they should go over the suggested tipping guidelines for your particular ship. Here are the industry standard guidelines for tipping, but please remember, tipping should be based on service.  If your service personnel did a fine job you should probably use the industry stand guidelines.  Depending on service, you may want to tip more or less.
 

Waiter:  $3.50 per passenger - per day

Busboy:  $1.75 per passenger - per day

Cabin Steward:  $3.50 per passenger – per day

Bar Drinks: Usually 15% is added to your bar bill.  If you found that a particular bar staff employee gave you extra good service, it really makes their week if you give them a couple extra bucks the last night of the cruise.

Head Waiter: Some cruises the headwaiters really can add to your cruise experience.  If they make special treats for you at your table or if you think they deserve a gratuity, a suggestion is $1.00 per passenger – per day.