make lists, make use of down time, reward yourself, concentrate on one thing, avoid procrastination, set personal deadlines, delegate responsibilities, set up a long term planner, employ a program like rescuetime, work in a team, be careful to avoid burnout
One of the best strategies I've learned is to remove all indications of time from your immediate vicinity when working on a project with a tight deadline. Trying to constantly judge your productivity vs. time is often a huge distraction, and every time you look at the clock is a break in concentration.
Nice submarine!