Best advice I ever received. Do it now. Start today, even if you can only spare ten minutes to fill a notebook with paper or set up a new file in the computer. Don't wait for big blocks of time. Always keep a pad and pen within reach.
Ideas are bubbles that disappear in a breath.
Don't limit your subject matter to what you know. Include things that interest you enough so that you will enjoy the research. Remember that writers are professional students. Once you start writing, end your day's work in the middle of a scene so that you can easily pick up the flow when you begin again. If you hit a brick wall with your story, go back and redefine your characters.