Ira Glass describes the problem of sucking with the eloquence of the master story teller that he is.
Jeff Atwood has the solution:
1) Embrace the suck - you'll keep sucking until you don't.
2) Do it in public - that way you can get feedback and learn how to suck less faster
3) Pick stuff that matters - the more important it is, the more motivation you have, and feedback you'll get.