There are various factors you can take into account when booking a cruise. It all depends on your preferences. The itinerary obviously is very important and you might try different itineraries depending on where you would like to travel to. Then you have to choose a ship! You can check the ratio between crew and passenger (the lower it is, the better service you will get). You can also check what year the ship was inaugurated or if it has had any renovations done lately. Then you can read about the type and variety of gastronomy it offers, how what extra activities and features the ship offers (casino, spa, gym, kids clubs, live shows...), The size is also something you should know. Large ships full of features for adults, youngsters, kids and toddlers as great if you are travelling with your family or parter. But some couples prefer adult-only ships that are focused on adult leisure activities and areas.