At the range I tend to shoot in an evenly distributed circle around my target, leading me to believe I am flinching or tensing up. On the double action trigger pull, if I decide to pull and I don't have enough pressure to get it to break past the final stage, I still feel that little "spark" in my brain that tells me of danger or excitement. I actually tend to have better accuracy with the double action. Something about taking the time on the long, slow trigger pull seems to help me.
EDIT: If there is a pattern to my shooting, it is usually up (haven't figured that out) or to the right (same as with the snap caps)