It’s a great thing, to sit down and just let the story flow out of the ether. Some days you can use this approach and let the page (screen) fill up with oodles of good stuff. Other days you manage just one or two sentences then sit there staring at the page wondering why the muse gods are mocking you today. If you find the mocking days are usually more frequent than the good days, then you need to change your approach.
It might sound like a stupid thing to say, but before you sit down to write you have to know what you’re going to write. “I don’t plot!” I hear you cry. Ok, that’s fine, I’m not saying you have to know where your story is headed in fine detail, but if you want to get your daily word count up then you need to start the writing day with some basic goals in mind.
For example, you could simply want to move your character from A to B in the next few pages. Or have a pair of characters engage in a conversation that reveals something to one or both of them. Alternatively, you might want to introduce a new character or setting somehow. Whatever it is, when you start to write, start out with a goal in mind. Then - and only then - will you be able to actually knock out some words on the days when your muse is in hiding.
Relying on your muse to be at your side every day without fail to fill your mind with wonderful scenes and witty banter for your characters is a doomed tactic. Trick your mind into thinking that you’re free-flow writing with small goals.
Happy writing, get that word count up!