Essentially, I'm untrained, so I just go with my imagination and try to put myself as solidly as I can into the shoes of whatever person I'm going to be playing.
I'm of the ilk of writers that feels you have to be open to the inspiration.
Essentially, I'm untrained, so I just go with my imagination and try to put myself as solidly as I can into the shoes of whatever person I'm going to be playing.