Some people treat writing as a "proper job", locking themselves away in offices with "KEEP OUT" signs on the doors and writing for two straight hours (no distractions, no Facebook, no Wikipedia black holes) until they hit 2,000 words.
Then there are people like me, who move from the sofa to the kitchen to the bedroom to Starbucks to the sofa, toting a laptop and a notebook, and writing sporadically inbetween episodes of Man V. Food until they hit 157 words.
See, I write very slowly and very concisely. Why say in 120,000 words what you can say in 60,000? (I'm looking at you, Stephanie Meyer. And you, Rowling.) I have a goal of writing 500 words a day - which is to say, I make myself write up until I get to around 500 and then shrug and say, "Good enough." If I write more than that, if I crack out 847 or 1000, then great; if I don't, then I don't beat myself up either. The way I look at it is, every word written is one less word to write, and sometimes the things you write when you're pushing yourself too much end up being kind of shitty. And I always find that when I go back and edit I have to rewrite those parts anyway - so if it takes me four days to write it well, really that's better than rushing it in one and then spending four days editing it. Don't you think?
P.S. It was my birthday last Friday! Officially not a teenager anymore...