Every writer looks at writing differently. Some do it because they love to create. Some do it to express themselves. To entertain. To become famous. To make money. Etc. Most of us write for a combination of these. With the exception of fame and money, these goals can be accomplished without too much trouble (other than, you know, the trouble of actually writing). Becoming famous, in particular, is out of most of our control, so I'll leave it alone.
So what if you want to make money by writing? In that case, you need to take your writing more seriously than most. You need to understand that this is a business. You need to consider yourself a pro.
This was the situation I found myself in a year and a half ago. If I wanted to take writing seriously, I couldn't be subject to ephemeral whims like "desire" or "inspiration" to write. I had to treat it like my job. What would my boss do if I said, "I'm not feeling it today. I'm not coming to work."? Or what if, when asked when I would finish a task, I replied, "It depends on when the muse hits me."?
(I should pause to point out that I still very much am subject to ephemeral whims. Every single day. All I'm saying is I'm not supposed to be.)
And I couldn't sacrifice my real job for writing. As many of you know, my real life is not a job I can walk away from. There will not come a day when I can quit my day job to work on writing for 8 hours a day. Because of that, I need to know that my time is being spent wisely. Of course all of my writing is worth it to help me improve, but when I start selling things, will it be enough to justify disappearing from my family for 2-4 hrs/day?
Like, I've made $7.20 on my Twitter fiction. While it was extremely cool to get paid for writing, I can't sell enough to justify the time. My BCS story got me $220 for about 30 hours of work. That's more worth it -- if I focused all my time on short stories, I could probably justify that amount of time (even if it wouldn't be enough to support my family).
Unfortunately, I want to write novels. Not having sold one, I limit my time. I look at what author's make (on average). I examine my process and keep track of production speed, constantly trying to improve until the day I can produce a novel in (what I consider) a reasonable amount of time. I'm kinda harsh, but I have to be. I want to do this, but there are some costs I'm not willing to pay, you know?
What about you? What are your goals in this writing thing (for those of you who are writing)? What are you willing to give up? Perhaps more illuminating, what aren't you willing to give up?