to be succinct here:
1: Bible - get the idea of your story and everything about the fictional world you are about to create down into a format yu can use for reference as you write.
2: Chronology - Everything in order. It is possible to write sequences out of a particular order, use your bible to know where you were going to put your sequences.
3: Minimize distractions - turn off the tv, have all of your tasks done, remain focused. Certain types of music to helpo influence what you are writing is highly recommended. This will come in handy when you go back through the entireity of your work to edit and streamline. Focus is the name of the game here.
4: Continuity and consitency - dself-explanatory. I lump these two together because they are necessities and walk hand in hand. When you get started, you will see if your protagonist is a tough guy but suddenly turns into a little whiner, be able to explain why the sudden change, for continuity's sake aleady have explaind the change in consistency. See how that works?
5: Use your imagination to it's fullest - your book is your baby. It's YOURS, don't let anyone deride your work or bring it down. Who knows, you might have just created the next new "thing" in literature?