If you are trying to decide between a departure port because of location you need to keep a few things in mind. How will you get to the homeport? Will you fly on an airplane, take a train, get dropped off by family or friends, or drive yourself and park? If you are arriving by plane or train you will need to make sure you have transportation arranged that will get you to and from the cruise terminal. If you are planning on driving yourself you need to keep in mind that you will probably have to pay to park. Or if you are getting dropped off by family or friends you need to make sure you set up clear arrangements with them. The biggest part of deciding on a homeport based on location is deciding on how you will get to the particular homeport and how far you will have to travel in order to get to your cruise ship's port of embarkation.
If you are trying to decide between a particular departure port because of cruise lines or ships you need to spend time researching what cruise ships sail from a particular departure port, where they sail, and what itinerary they travel. Some cruise lines and ships will sail seasonally from departure ports and other cruise lines and ships will sail year round from a departure port.
I suggest narrowing down your departure port choices based off of the price of the cruise, cost to get to the port, and value of the ship & itinerary. Make sure decision carefully and after doing plenty of research.