Never pump yourself dry, advised Ernest Hemingway
I find word counts very interesting. I tend to get everything down I want to say, then come back and craft it - it may be the same day/session, it maybe a fair while later. Which makes the word count flattering to start with, but then the working on it often means I gets shorter (hopefully) which makes it seem (by the employment of word count as guide) like I have been doing less than nothing.
How much I write in a day often depends on how quickly I craft the opening paragraph. Sometimes it comes instantly - a scene, a conversation, an anecdote - but at others I sit staring at the screen turning words around in my head until eventually they come down in an entertaining order. Or not. Best thing to do then is go for a country walk or a few lengths of the local pool as the absence of distractions often leads to that elusive first sentence. Get that down and I'm on track for the rest of the day - what's left of it!