Dean Wesley Smith is starting a new series of posts titled "Goals and Dreams 2012," and I really like the two posts he's done so far. His first post is about how, yeah, you're gonna fail, but as long as you're making progress, don't sweat it. Writers tend to be perfectionists, which is a double-edged sword--I think on a certain level, a writer needs to be a detail-oriented perfectionist, otherwise you'll forget plots, have incoherent characters, and write long winding sentences that don't actually make any sense.
But you have to be wary of what are called in self-help/psychology circles the Three Ps: Perfectionism, Procrastination, Paralysis. If your perfectionism gets out of control, you'll put off actually producing anything for fear it won't be "perfect." If this continues unchecked, you won't ever do anything, because you might make a mistake.
I think the balance is achieved by just making sure you're moving forward--or just forward enough. To take the examples Smith uses: He had certain weight loss, fitness, and short-story writing goals that he didn't meet. He did, however, write a bunch of stories, exercise more, and lose some weight. By "failing" to meet his story-writing goal, Smith made $3,500 per year that he didn't have before, very much enjoyed himself, and proved to himself that he could crank out stories at high speed. I have no idea whether this applies to Smith or not, but with some people a small reduction in weight or small increase in fitness can have an outsized impact on their blood pressure and cholesterol levels. So the larger goals (more money, developing beneficial work habits, better health) are being reached even if the specific goals for 2011 were not.
The second blog post has some really nitty-gritty advice about making time to write. Possibly the most important bit is to discuss your new and exciting scheduling needs with your family and significant others at the very outset. I don't mean to insult your loved ones, but the world is full of people with some really stupid ideas about what writers do. I see this a lot particularly with younger writers--they hook up with some fine young thing who wants them because writers are all cool and arty and sexy and alcoholic, and then they don't get any support for their need to spend long hours cooped up by themselves with a computer (while not suffering from a debilitating hangover) like some nerd. It doesn't get any easier once you start making money--I have people in my family who have never understood that freelancing and being self-employed are not the same thing as being unemployed, and they have never understood that not being tied to a 9-to-5 schedule doesn't mean that a person doesn't have to spend most of their time working. (I'm not sure how they thought I was supporting myself all those years, although with that generation "a man" seems to be the go-to answer to any and all questions.)