Just do it!
Okay, so that's a pretty shallow response. But remember, that's what it all comes down to. If you don't at some point learn to 'just do it,' then all the anti-procrastination techniques will become another form of procrastination.
But some things that make it easier for me are:
1. Starting a task with no intention of finishing it. Sometimes just starting the dreaded thing makes me realize how easy it really is. If it turns out that it really is hard, then I might try something else.
2. Scheduling. This doesn't always work, but devoting a specific hour to a task makes it kind of like a job, or a class. I have to do it during that one hour, but as soon as the hour is up, then I'm free to go, and I don't have to think about it anymore.
3. Cultivating interest in the task. When I'm at my job, I don't really want to be there, but I find ways to make it interesting. I remind myself that I'm getting paid, that I'm becoming a better worker, that I'm getting closer to the end of the day...whatever helps me at the moment. Even if it's a crappy job. For homework, I try to think things like: This is an opportunity to get a better grade, to learn about a useful subject, blah blah blah.
4. Realizing that procrastination time is not as enjoyable as actual free time. It's easier than doing the task, but it is not as enriching as having the task behind you. It is usually spent websurfing, daydreaming, or studying the texture of the carpet. Is it really so bad that you have to put yourself through all this?
As a strange acquaintance of mine used to say: "Procrastination, is like..."
Well, nevermind that one.