Depending on which writer you ask (and when), there seems to be no end to the different types of answers you get to the question "What's the hardest part of the writing process?".
For some, coming up with ideas is like pulling proverbial teeth. For others, ideas are a dime a dozen and the execution of the ideas is actually the hardest part. Some writers find crafting an exciting and original opening chapter to be the hardest part (and this can be extended to cover opening scenes, paragraphs, sentences or even the first word, as well). Once they're rolling, it's all down hill (probably not the best of metaphors, there).
Some have trouble fleshing out their characters, or choosing a setting and won't even start until they have everything in place. Still others feel they need to know the entire structure of the book and have a detailed outline in place before the prose can start to flow.
Quite a few writers feel it's the swampy middle of their books that are the hardest to write and get past. I know I've personally left quite a few still-births at that point and I feel for my brother and sister writers who lose their way in the everglades of lost threads and overzealous plot devices. That middle can be a dangerous place.
In truth, there seems to be no end to the number of things writers find "the hardest part". I haven't even mentioned endings, rewrites, theme development or killing your darlings; all brutally difficult and painful stages in the writing process. And let's not forget that for some it's not even the writing part of the process that they find difficult. There are those who can get manuscripts in shape with little effort, but wake up with cold sweats when they think about submitting or even contemplate the idea of letting someone else read their work.
For me, though, the hands down, king of the hill, cock of the walk, queen of the prom killer is -- choice. Now, I'm not talking about those million choices every writer has to make between "It was a dark and stormy night..." and "...Bobby realized it was all a dream". Though those are tough, they don't particularly scare me. What scares the little malteasers out m'butt every time is choosing what to write. Or maybe a better way of putting it is choosing what not to write this time.
The biggest problem here is that I want to write everything: horror, mystery, sci-fi, fantasy, hardboiled, time-travel, thriller, romance, etc, etc. I love and want to write them all. For short work, it's not such a trial making a choice, because you know you'll be done soon and you can try something else. But longterm committment to a project, like a novel, is another matter. The conundrum is that I think I have a predilection for longer works.
So more often than not, I end up making no choice, or diddling around with shorter projects. It would help if I didn't have ideas for a wide variety of projects, but I'm one of those writers who feels ideas are a dime a dozen. And I've got about six bucks worth of stuff rattling around my noggin.
I've never really been a planner or outliner, but that's exactly what I'm currently doing in an attempt to focus and actually produce something. We'll see how it goes. I don't want to scheme the creativity out of my work, but I'm hoping a plan -- or path -- laid out for me to follow will keep the shiny objects on the side of the road from distracting me into being the king of partials and owner of the hard disk with the most pointless vignettes in the English speaking world.
We'll see how it goes.
Unless I start work on that eight-volume opera I've been thinking about...