The vast majority of my cruises are booked within six months of sailing. I have a hard time booking a year out because "life" can get in the way and I have to cancel.
I am not super picky about my cabin location. It just has to be a balcony or better so I have no problem doing a last minute booking. I have found that booking around final payment time you can get a decent price.
The main criteria is itinerary so when a decent deal pops up then I jump on it.
My definition of a good deal is: $100 - $125 pp/pd for a balcony or mini-suite and $175 - $200 pp/pd for a suite. This can change based on itinerary. I may pay a suite price for a balcony if the itinerary is good. i.e. Australia, Med or South America.
I always book hotels using Priceline. I have used Priceline at least 50 times and have only been disappointed once. That was the first time I ever used them and didn't really know what I was doing.
I rarely use cruise line transfers. For two people it is almost always less expensive to use a taxi or shuttle service instead of the cruise line. It is also less of a hassle then standing around for an hour waiting for the bus to fill up. I also "really" hate buses.
I also rarely use cruise line excursions. I will research and find private tours that do and see more than the cruise line. They are almost always less expensive and better. I do private excursions because I want to take time to stop somewhere if I want or bypass something. It is one reason we rarely share an excursion with other couples. It's a great way to make a private tour very affordable but I still want to have the flexibility. It doesn't mean I'm anti-social. I just want to get the most out of it for my wife and I.
The big thing is to constantly keep checking for cruise prices and itineraries you want and then be able to book them ASAP. They usually don't last long and if you hesitate you lose it.