One of the best parts of starting a new story is being carried away with it. I was excited while I was researching, and as I lay down my chapters, I'm learning new and interesting things about my characters that propel the story along. This is the fun part. Oh, I know that there will be difficult times ahead; there have been difficult times already. I think it's the level of excitement you feel - the impetus that makes you write the story in the first place - that gets you through the speed bumps.
In the interest of keeping in practice, I have written stories that did NOT interest me and I had a hard time plodding through them. I'm a compulsive finisher, though, so I always get to "The End." It was still a good exercise in plotting and character development, and even in the stories that didn't excite me much, there were moments of clarity when you felt like you were pulling it all together.
Another aspect of my latest endeavor is that it lends itself to a series. I'm not keen on writing/reading series' of books as a rule although there have been some that sucked me in. My personal opinion is that it can get old and lose its appeal after you've visited the same place more than once. The thing that appeals to me in my own imagination right now and what makes me think this could continue, at least for a couple of additional books, is that although this story is focused on one main character with a unique history, there is a civilization of these characters that have splintered off into various sects that could step forward into their own spotlights. Food for thought, but I have to get through this one first and see how it flows.
I find myself writing much more carefully, paying more attention to mechanics. My regular flow is generally much more haphazard and I imagine that's because it feels much more like standard subject matter. Slap it down and clean up the mess later. This time, there is a lot more thought going into the details - and so the details are popping out more. Every now and then something just strikes you - and this is one of those times.
So while my muse is sitting squarely on my shoulder, I'm laying down chapters and charting details and characteristics (including those I will likely never use). These are the days when writing isn't a chore, or a job, or difficult. These are the days when it's fun - the days that remind you why you write in the first place!