My mother raised an eyebrow when I told her this, as though I were sinking into a world of insanity and imaginary friends. So maybe I better explain.
Each writer has his or her own way of doing this. Sometimes you are faced with two opposite ideas. Both of them seem to lead in the right direction.
For example, my princess needed to be rescued so she could then try to save her kingdom. Should I have the bad guy "rescue" her or should I send some new friends her way?
I asked the princess but she only said that she must save her kingdom and did not care who saved her.
I ask the new friends and they eagerly told me that they wanted this opportunity to prove their friendship. After all, they argued, this was an appropriate culmination of their previous scenes with the princess.
I asked the bad guy. It was his idea that he should be allowed to rescue the princess in the first place. That was part of his plan -- to win her heart, if possible. However, when I asked him again, he was quick to insist that she must remain in her current predicament until he was ready for her. He had given this a lot of thought and decided that, if she were to be rescued too soon, she would only get in the way of his plans.
I obviously need her rescued now, and, since the bad guy wasn't willing to do it on my timing, then her new friends were granted their scene in the story. But I wouldn't have known to do this if I hadn't considered the motives and purposes of each party and the possible repercussions of the plot line I decided upon.
So how do other writers do this? Do you ask questions of your characters? Or do you have a more sophisticated method?
Have you ever had two possible paths for your plot to travel?