I find that I pluck less when I consciously think of pulling my elbow straight backwards while I hold on my target. The bow hand should push toward the target on release, and the draw hand (think 'elbow') should follow through in the directly opposite direction.
As to the release, think this: Hold your release hand perpendicular to the ground, like a handshake. Now draw a line with a marker on the up-facing side of the index finger. Upon release, that black line should slide across your face, and your hand should move toward your shoulder. This will require a subtle rotation of the hand on release that lands with palm facing your shoulder. If you can achieve that, it will make you more consistent.