I have always wanted to write a novel about the first vampire and having all the disadvantages that go with it in a fantasy setting. I struggle with a couple things, first managing the character building in a novel usually I lose track of who's who and what's what.
For this issue, writing down your charaters before actually putting them in your chapters will be helpful.
See, I'm a writer of harem genre, and with a huge cast that I wanted to make 'human', I have to be consistent with their personalities, hence I keep notes on them. And it's effective.
I also have issues maintaining the desire to write at times, usually it becomes a chore and I just drop it. I tried already to write a vampire novel and dropped it, after realising I wanted the story to go a certain direction but couldn't figure out how.
For this one, I have suggestions:
1). Change the way you think at your hobby/writing. Yes, it is a hobby, but without dedication to it, you'll only fail yourself. It will sometimes look and feel like a chore, because yes, it is. Not everything is fun and games in writing. (Speaking from experience, it's a never-ending suffering, but we pick our poison
)
2). Establish self-discipline and a routine. Like, for me, a month of writing is followed by one or two months of break where I do whatever I want. I finish my manuscripts within that three-four week period, hence I managed to write 15 books to my main novel.
3). If you are a planner type of writer, planning and plotting your story will help you know what to do next, or at least, have a semblance what is to follow for your current chapters. As I am not a pantser type of writer, I can't offer a concrete advice on how to workaround its weakness.
Any advice is helpful, I am currently writing again, another attempt at my idea but with a darker setting than the past.
As always, these advices are what worked for me. It's not the standard, but it might be helpful if you try it. Still, at the end, enjoy your writing, though mix in a few of self-discipline because writing is like a muse that we need to work hard on wooing before we get her cooperation.
Hope this helps!