I sometimes get bored with my stories as I'm writing them. This makes it even harder to carve out the time and energy to sit down at the keyboard. So with my latest I'm starting with the good parts. I write whatever cool scene strikes my fancy without worrying about consistency of character or time line. I have a general idea of how I want the story arc to go, so when I have enough cool scenes to achieve this I'll start putting them together, and then I'll worry about making things consistent. I don't know if this is a good idea, but at least I'm more enthusiastic about working on my story.
So what process do you guys use? Start at the beginning and write to the end? Write the ending first? Outline? Exhaustive character sketches?
Sidebar: the interviews on the I Should be Writing podcast have good descriptions of how the pros do it, IMHO.
I find myself getting bored sometimes. It usually happens when I finally know how the story's going to end, or when I get to a lull in the action and want to get to a good scene coming up. You just gotta fight your way through it.
When I write a short story, it usually starts with either dialogue or a good opening line in my mind and just goes, but I've spent a couple of days at that point thinking about the story, where I want it to end up, et al. Short stories I usually finish in a few days to a week, so I can keep everything straight in my head, and I usually don't have a lot of characters. Also, I don't start with the cool scene, even though I know there's something good coming up, because it helps me to better the cool scene if I know more about the characters and the situation.
As for a novel or even novella (or multi-part short-story, which some of my erotica tends to be), I'll again think for a couple of days, then start out where I want the story to begin, keeping everything in my head. I'll keep a notepad handy to make character notations or other important bits, but for the most part I'll just go. If I get to a point where I need to remember a character's eye color or height or something, I'll put it in square brackets and come back to it later. That way, I don't have to break up the flow of the writing. Once you're on a roll, you don't want to get off that roll.
After a few chapters, when things start to become more concrete on the page, I'll write a paragraph outline -- basically, a six-or-seven-line paragraph abstract for each chapter, or a three-paragraph short version of major story arcs. Just to keep track of what's going on. Then, as I write the story, I keep the outline handy and cross out stuff I write as I go. (I've got the clean file on my computer so I can always bring it back and reprint as needed.)
The most important thing is to keep going, even if you pause from a story because you have a great idea and need to write another, even if you have something you want to write that no one but you will see. Just keep writing. Keep those neurons going. And remember: revisions are not negative criticism.