I shoot all kinds of targets. Sometimes I shoot blank butts, 3-D target, flat picture targets, and I'll even put an orange dot in the middle of the kill. Doesn't matter, I "aim small to hit small" (positive feedback is very important so missing is left out of my vocabulary).
I think there is strong merit to putting an artificial aiming dot in the middle of what you want to hit. You can visualize this spot on live animals, sometimes better than you can concentrate on a shadow, crease, or "hair".
My signature line is the lesser of the Gospels that I believe in. (The greater Gospel has 52 books).