I've never in my life been much of an outliner, not even in school to study. That being said, I ahve attempted to outline a couple of my longer fics. It always ends up getting scrapped though.
I tried outlining my L&C/Xena/Herc crossover - Soul Desire. I did about half of it and then noticed that as I wrote, everything changed. The basic storyline stayed the same, but things I anticipated putting in Chapter 5 got pushed to Chapter 7 because I expanded the story as I wrote it.
I outlined part of my epic length Contractually Bound. I had the same problem though. As I write, I tend to embellish the details, making the chapters longer than I initally thought they would be, and finding better ways to handle certain things. Or, I find better places to end chapters. So the outline got tossed to the side pretty quickly.
I'm currently working on Specimen S, a "what if" alt world scenario. Again, I tried to outline, but only got about 6 chapters in. As I started to write, the entire outline changed as I found new angles I wanted to explore, new moments in Clark's life that I wanted to play with.
All in all, I do think that outline can be a good thing, especially on longer/more complex storylines. Things like a lot of time travel would be something I would probably want to outline, so as to keep my own mind straight.
However, we all have our own writing styles, and what works for one might not work for another. And I am most definitely a Discovery Writer. I like to see where my muse will take me as I go along. I might have a vague idea of some of the stops along the way, but I don't always know the exact route we'll take to get there.
Even in my original fiction stories, I pretty much never outline. I just sort of let my muse run wild. For me, I find that my stories actually wind up stronger than way, inside of trying to pigeon-hole myself into a pre-written outline.
