One thing that I learned from bicycle racing (actually, I am not much of a bicycle racer but I do triathlons - biking needs work) is the power of momentum. In bicycle racing the way to do better and use less energy is to pedal very, very fast and powerfully to start with, give it 120% and once you are up to speed, you can simply maintain a good even cadence.
I have often used this technique even with my car which tracks my Km per L (of course I don't do major jack rabbit starts but I do get up to speed quickly and then go easy on the accelerator). I find this technique is the best way to maximize mileage. Save energy and get ahead faster.
I use this same technique to getting projects and tasks done. I find if I can simply start the project fast, I can often use the momentum to carry me through to its completion. So the key is to get started fast. Some techniques I use for this are:
1 - Ask someone to help start. Often just having someone else help gets things moving.
2 - Know your high energy times and start projects with a burst during one of those periods.
3 - Avoid distraction. Focus 100% on the task or priority that you are trying to get started on. Turn off email and the phone. Close your door. Get rid of papers on your desk.
4 - Know your outcome. The clearer you know what you want to accomplish, the more likely you are to accomplish it.
5 - Set a time limit. I know I can do almost anything for a short period of time. By setting a time limit like 15 or 20 minutes to work diligently on a project then give myself permission to quit, I often develop momentum.
6 - Be prepared. It is easier to develop and maintain momentum if you have all the tools and information ready.
7 - Finally, just do it. Dig in hard. Push hard. Remember the bicycle. A few hard pushes to start make things much easier to finish with less energy.
Using these techniques for gaining momentum can help you move any project forward faster and more easily.