For me, it usually (not always) starts like this:
1. I get an idea I can’t wait to write about.
2. First few pages, and sometimes more than a few, I write fairly fast.
3. Eventually, I hit a roadblock where I question the direction the story should follow. From there, several things can happen:
4. I think for a few days, running the whole story in my head, visualizing different paths my characters would take, then continue writing. Or…
4a. If my story upon reruns doesn’t seem to take off, I would comb through the whole script and see where things don’t work. The next step is either rewriting/taking out scenes or starting all over again. The last one is rare, but it happened.
5. The process more or less repeats itself from the beginning.

What Helps me to Write a Believable Story?
1. Music. It sparks my imagination. I like to listen to it while I’m at the gym, exercising on the elliptical. The right choice of music is paramount, otherwise it can be distracting.
2. Anything that gets my mind ‘floating’ unattached to anything. This can be a shower, stretching, or walking. Just forcing myself to be creative produces a very mediocre result. The most vivid imagination occurs when you just let your mind go.
3. Emotional palette as shown in the image. One day I decided to map my story emotionally: in terms of color. It is something to help me see the story from a different perspective: color-mapped emotionally.