There is no one answer for fighting laziness or procrastination. Most tasks are defined by a deadline or consequence if not finished -- don't wash the dishes, they grow mold and smell bad. Other, smaller tasks, like vacuuming the rugs, don't have consequences for a long time and so are easier to put off.
Two good methods are deferred reward and powering through.
Deferred reward is one of my personal favorites. If I am planning something fun -- an evening of bad TV with junk food, for example -- I will not start the fun early in the day, meaning to "get to" the job soon, because I will end up delaying until I "can't" do the job. Instead, the fun will be my reward for working first. Delay your fun and it will be more satisfying.
Powering through is one I have to do more often than I like. This is where there is no immediate reward or goal, just something you have to do, and you put it off because really, you don't want to. In this case, the only solution is to take a deep breath, sit down, and power through the task until it's done. In writing, this is the best way to get words on the page; if you have nothing written, you have nothing to edit, and even a lousy draft is better than an empty page.