I'm a great believer in the value of goal-setting. To me, it's not so much about hitting a target (which is just as well since I miss most of mine ) as it is about the benefits of aiming for one in the first place.
That said, I think if you always hit the mark, you're not stretching yourself enough. I may not reach most of my goals, but I achieve a lot more than I would if I didn't set them at all.
When it comes to writing, a lot of people set goals for daily output. Of course, you have to go with what works for you, but I tend to shy away from wordcount targets, preferring a more general 'Write a new flash fiction in the first half of September', 'Finish chapters six and seven by this Friday' etc.
Now that Summer's over and the kids are back at school, it's time for me to review my 2009 writing performance so far and reassess my end-of-year goals. I'm a little behind on my flash fiction/short story target, but not by much. As for novels, I need to step up to the plate and finish the revisions for Waking up Jack Thunder, which I wanted to have done by the end of August (new target: end of September). After that, I've another novel, Champion: A Union of Snakes, to revise/rewrite by the end of December, so that I can start a new project on January 1st next year.
How about you?
What writing goals do you set for yourself and why?