"I've learned the key to finishing such a big project is to do something on it every day. It doesn't matter if you spend just a couple of minutes or hours so long as you don't have long periods of ignoring it."
-- Paul Mulwitz, guy who builds planes in his spare time
This is a productivity tip closely related to procrastination. How many times do we procrastinate because we haven't touched a project in a long time, making the steps ahead are uncertain?