A suite is a cabin with at least two rooms, right? We thought so, too. And then some cruise lines started offering "suites" with only a curtain separating the living and sleeping areas. Now, we're even seeing some suites that don't have that.

When in doubt, check the diagram of the room layout — all cruise lines offer those on their websites — and see if your "suite" actually is one, if that's something you feel strongly about. We care most when, for example, we're traveling with an insomniac friend, a young child who has to nap, or an older parent who goes to bed early. The rest of the time, it doesn't really matter to us. 

To us, a balcony is something you can walk out onto, and preferably sit on. It's a great place to sip morning coffee or enjoy a cocktail before dinner. But some cruise lines started offering "Juliet balconies," with a sliver of space on which to stand but not much else. And now, some lines — usually river lines, but increasingly (such as the case of Celebrity Edge) ocean lines, too — offer "balconies" that are really just sliding floor-to-ceiling windows. We would prefer to think of those as really awesome windows rather than sad balconies, but that's just us. 

Ever been at a party full of people you didn't have much in common with? Pick the wrong ship, and you'll be at that party for days on end. Whether that means people who actually party way more than you do or who are much more quiet and serious than you like your vacation to be, ending up with the wrong crowd is one way to spoil a trip. Be sure to do your research — our line and ship reviews, for example, can help. 

It's true your cruise includes your cabin, your meals, and most entertainment. But on a lot of ships from mainstream lines, most specialty dining restaurants come at an additional fee. And on most of these ships, eating in those specialty restaurants really is the best way to have a stellar dinner each night as (for a modest fee) you get a big upgrade from the main dining room.

We've said it before, but we'll say it again: When you're figuring out the total cost of your cruise, do the math on how much onboard extras will add up to. If you have a latte every morning, soda or beer at lunch, wine with dinner, and you book shore excursions and onboard activities such as massages or wine tastings, you could end up with a hefty bill by the end of your trip. In addition, you'll want to factor in the required port fees, as well as the automated gratuities, which are common on all but the luxury lines, and even extras such as gym classes.