Write. It sounds cliche but sit down and write. Write anything you want to. If you are comfortable, or think you can be come comfortable, then set up a blog, and write there. Get in the habit of writing, of getting your thoughts out there to be discovered. It will help you on the day you have to send your manuscript off to the editor or to your beta readers.
And, the other BIG thing that has proven extremely helpful to me: Develop a circle of friends able and willing to answer questions over just about anything at just about any hour of the day or night. You may think that you will be able to hold yourself to a set schedule of only writing between X and Z hours, but having friends who are awake and able to talk on the opposite side of the day from this in reserve remains a good idea. There have been times when I know I have been very, very grateful to my friends who work the night shift, because I was on a roll late into the early morning and hit a snag. Those friends still up provided just the nudge I needed to finish out the scenes I was in the middle of. If I hadn't had them, I am not sure the story would have been finished the way it is.