I prefer to use different writing techniques depending on the book that I am writing. For most of my writing life, I used the "meandering method". That's the phrase I use to describe making it up as you go along. It is perhaps the most liberating and sometimes rewarding way to write because you never know where your story is going to end up. Unfortunately, this method tends to prolong the writing process (for me at least) and also creates writer's block. When you make things up as you go along or rely on improvisation to tell your tale, you often end up creating a situation where you don't know what to do next. Writers who use outlines rarely face writer's block, because they have mapped out their stories long in advance. The downside to using outlines is that if you don't allow yourself to deviate from your outline you are likely to write a story that's rather tame and predictable ultimately taking all the drama out of your story.
Professional writers (or perhaps I should use the term "writers who work under contract", don't have the luxury to spend 14 years trying to figure things out as they go along as Tolkien did when he wrote The Lord of the Rings. These writers have to submit premises and outlines to their employer under strict time limits and thus end up with very structured stories. You'd be hard pressed to use Joseph Campbell's "The Hero's Journey" archetypal story model if you don't use an outline. Unless you're keenly farsighted, you'll end up trapped in revisionist hell trying to sort things out without some kind of outline.
That's why I prefer to use an amalgamation of techniques when writing my stories. If one of my stories is heavily laden with dialogue, I'll generally write out the story like a screenplay and worry about exposition later. If a part of the story requires me to describe complicated action scenes, I'll outline these scenes so that I know what's going to happen in intricate detail.
I find that if I'm writing an epic story that takes place over the course of several books, it's best to create a story bible just like television writers do for their shows.
To sum it all up, I find that using different writing methods gives each story I write a unique personality and style. If I use one writing technique, I tend to fall into predictable patterns that sometimes stifle the creative process. But in the end, my advice would be for every writer to use whatever writing technique works best for them.