Shadow of Light Dragon wrote...
Mostly I only get blocks (as opposed to 'I just don't want to write right now' syndrome)
This is an important distinction! As a person who tends to sort of dither around for a while, then make a decision and jump in with two feet, I plunged into fanfiction and quickly got to feeling like I
owed the Invisible Audience something. It was getting a bit stressful there, and I have to explicitly give myself permission not to write if I don't feel like it.
If I do feel like it, and I'm having a hard time getting the words to come out but I *do* know where the story's going, I write anyway. Badly. Like, I write the simplest and most banal record of what I see in my head. Usually, within a few paragraphs I'm over whatever was keeping me from going forward, *and* I have a rough draft I can use as a starting point for rewriting the difficult bit.
If I don't know where the story's going - usually actually not knowing how a character would react to a situation - I tend to want to hash it out with people. Once I feel like I've got a good handle on what's a reasonable in-character thing to do, I'm good to go.
Lastly, if you mean, "I want to write but I don't know what, I don't have any ideas," I can't much help except to say that, in my personal experience, doing something begets more of it. So start with a prompt, from the thread here or a prompt generator or a fan community on LJ or elsewhere, and write the most obvious thing that comes to mind, even if it seems trite or less than clever. Do that a few times over, and see if the ideas start coming.
(IME, it's not the ideas that are the hard part. Ideas are kind of easy, once they get going. It's the
execution, the giving the idea shape, that's the killer.)