Well it's only a descriptive theory; it doesn't actually tell you what to do about the fact that accumulated cognitive dissonance is making you procrastinate. Still, I think there are some practical applications:

• Consciously try to minimize cognitive dissonance when you tell yourself to work and don't.
• Develop some sort of unambiguous decision rule for deciding when to work and when not to.
• If you set out to do something, try to actually do it without getting distracted, even if you get distracted by something that's actually more important. (Or if you get distracted by something that's actually more important, make a note of the fact that you are rationally changing what you're working on.) (Now that I think of it, this rule actually has more to do with avoiding learned helplessness due to setting out to do something and failing.)