Before you choose on which side you want to stay, inspect the layout of the ship. Determine where the noisiest and quietest parts of the ship are. If you're seeking peace and quiet, you may want to avoid noisy public spaces like dance floors and casinos. The layout should tell you on which side these public areas are, so you can plan accordingly. If you want to be closer to the action, consider choosing the side with the most communal activities.
Ascertain whether you will be traveling south or north for your trip and whether it is a full-circle cruise. If you are traveling north to Alaska, it's better to book a room on the starboard side because of the phenomenal mainland views that side offers. If you are traveling south to the Caribbean close to Mexico, the starboard side will provide you with picturesque views of the country.
Determine how the ship will dock at each port of call. If you are keen on seeing the port while you are in the harbor, choose cruises that will dock on the starboard side. Otherwise, you can be left looking at the ocean for many hours. If that's OK with you, choose cruises that dock on the port side.
If you are traveling north, you will be greeted by a sunrise every morning from the ship's starboard side. On the other hand, when you are traveling south, you'll see the sunset from your window every evening. Depending on your preferences, you can choose a starboard sunrise or sunset.