Since I started writing fiction, I've been studying the art. I started in the library and checked out several books on writing, some of which resonated with me, while others did not. The first one I read was "No plot, no problem". Before I realized that it was also the manifesto for National Novel Writing Month, I found some great advice starting with "just get started and let your characters do the work for you." (That's not an exact quote, just my takeaway.) More recently, I read Stephen King's "On Writing" (brilliant, by the way and probably my favorite book on writing) and just read a passage in Dean Koontz's book "Relentless" that both eschew the practice of outlining.
I come from a software engineering career, which I still work at, and there are similarities to the way I like to work. I have never enjoyed long spans of planning before implementing my software. If I did, I always ended up finding a better way once I got started, so planning exhaustively seemed a waste of time. That's not to say that a little planning wasn't useful, I just never found it of value to do all of the planning, then all of the implementing. I'm a creative person, so I always thought of more creative implementations and often better functionality than was originally planned.
I'm finding the same thing is applying to my writing. I do a little planning, then some implementation. If I've planned ahead, I often find that when I'm writing, I come up with something better than my original plan. If I run into a block, I take a walk and let my mind wander for while. Often, something occurs to me that's way better than my original plan. The subconscious mind is a magical thing.
I have a good friend who's the planning type. We had lunch and I asked how his book was coming. He told me that he'd been outlining it (over 100 pages of detailed outline) for 6 years. In addition, he'd been working on improving his writing skills. While I'm looking forward to reading his book one day, I can't help wondering where he'd be if he'd just started writing it 6 years ago. In less than one year of writing fiction, I already had two drafts of my first novel. It may take me another year or two to get it right - I know my writing has certainly improved since the first draft - but I have something to show for my work. I have something reviewable, workable, and can take pride in it.
When is the last time you bought a software specification over working software? When is the last time you went to the bookstore and bought an outline instead of a finished book? I'm not saying that outlines are worthless, for some people they are essential. For me, they are a way to get started. The key is to be unafraid to start. Once you do, you have a chance to finish.