...and by those stories, I mean one where you blast through most of it at a creative pace that has your muse running to keep up and then get within a hair's breadth of the end and you come to a grinding halt?
This only happens to me with short stories, because I plan my novels in enough detail that I'm sure of the end before I start writing (or maybe I should say an end, because it can always change before I get there). I'm in the middle of, or should I say, a hair's breadth before the end of a short ghost story I'm submitting to S D Neeve's IWACA magazine, and I was running at full pelt at the plot when I made the fatal mistake, I took a break. Well, actually, I was forced to put my computer down to be, y'know, social - have lunch, then wave my arms in front of a choir.
Unfortunately, that meant I had time to think, to go over my ideas, to think of different ways to end the story and I got myself into a dilemma. I think if I'd just carried on, I'd have gone with instinct and followed Zen and the Art of Writing, which can sometimes wend its bountiful way to the end of a story without much conscious intervention from little ol' me. But my brain got in the way of serendipity and now I've been pondering on the ending for two days! Add to that a word count I have to meet of 2000 words max, which is a challenge for me, because my short stories usually start at about 5000 words and I have put myself into a real pickle.
Actually, looking at it in the light of the word count, the original story I wanted to write would never had fitted, I had too many characters and additional plot development. It would have built up the suspense more slowly, but I can't afford that in words :). So I have to come at the story from a different way - pack a small punch earlier on and build more rapidly to the climax.
I've now had a lot of practice on very short stories, the art of capturing moments in 100 words with drabbles thanks to FB3X Drabble Cascades, and I think some of them have worked. I've been writing much longer works too for a long time and it's where I'm most comfortable. I also seem to be okay at the novella length story. 2K - well 2K is killing me ;P. But, I'll get there, I have an idea in mind for my ending now, I just need to shape it into something that will entertain. :)