If you are a member of a warehouse club, check them out, too. Just have some idea of where you'd like your cabin. I booked an NCL cruise out of New York and was able to get the cabin I wanted, but I was looking at a Holland America cruise for next year, and all the cabins they are offering on the deck I prefer are too far forward or aft. If I decide to book it, I will pay the extra $100 or so and book elsewhere to get the cabin I want.
I also strongly recommend booking a cruise that includes Glacier Bay. Only certain ships have permits to cruise there. Recently a cruise line lost their permit to cruise there due to environmental violations. I think it may have been HAL, but I'm not sure, and I don't know when the suspension starts, so double check on that. Glacier Bay is spectacular!