Are you ever writing something and you know what you want to write and where you want to take your story, but you don't know how? I'm currently having this problem. I'm writing a screenplay and I pretty much have the entire story outlined, but I've gotten to a point where I don't know exactly how to write what I want to write. The situation (that the characters are in) is a bit complex and it involves putting myself in the heads of my characters to write about something that couldn't be more foreign. In short, it involves an accidental murder and the emotional reactions of those involved. How do you go about putting yourself in the mind of a character that you can't possibly understand? How do you realistically write something that's so far removed from what you know? I would have put this in character development, but it's just as much an issue of plot. Mods can move it if you want to.
Keep flash fictioning your characters write 1000 word stories making character one the snippet's MC. It will then fall into place. Concentrate less on a rigid goal more on the creative art element
Thing is as you write you will understand and learn to know your characters. It is an evolving process. Some research and imagination will help but above all just write them/
Yes, like Elgaisma said, just continue to write your characters. I wrote a short story for a contest here, and my problem was that I knew the ending, I just didn't know how to reach it. I knew the end result, what effect I wanted to leave, but I didn't know how best to use the characters to do it. All I can say for your case is to write it, leave it alone for a day or two, and then come back, and see what else you would like to add or take out.
I've been on a several month hiatus from this script, actually. The characters are all pretty well developed, but it was writing them in this particular way that made it difficult to continue. I know generally how they react, I just can't get the specifics together. I couldn't properly write how I see them reacting, even though I know the emotions they feel. My script is really poorly formatted at the moment. It's supposed to be a screenplay, but it's written more like a stage play that mentions certain cuts and shots... just a bastardized version of the two, really. And I'm up around 50 pages, so probably closer to double that in proper screenplay format. And there's lots and lots of dialogue to develop them. My problem doesn't stem from not knowing my characters well enough, we're quite well acquainted, I just haven't been able to put my head in this specific space. I've been suggested what you're saying before, such as writing the characters in another short piece of fiction to get to know them in different situations outside of the plot of the movie, so I may try that. Researching this in particular... might be difficult? But maybe I could find a way? Hmm...
It sounds like you know where your characters are going to end up, so why not try working backward from there for a little bit? I sometimes find that helpful, especially if I have a story with a twisted/complicated plot.