When I shoot trap, I always know when and where the clay is going to go, but in the field of course, I never feel prepared for the flush...even though I can tell when my dogs are getting birdy, it seems like I am never ready and when I am, the bird is gone!
Back when I was much younger one of our hunting group consistently shot about 23 out of 25 on the trap range. However, he just couldn't hit a thing when it really counted (hunting).
As Lainee said, in the "grand scheme of things" (hunting), thinking too much about the shot will often lead to frustrations. Habits and expectations must be nurtured.
The first thing you need to do is make sure your gun consistently mounts toward the target. Put a small piece of tape on a mirror. Do NOT see the gun sight or barrel......look only at the target as you hold the gun in a normal walking/hunting motion. Focusing only on the tape, snap your gun up to a shooting position and then visually check the alignment of the barrel with the target. Does the gun consistently point at what you are looking at? Practice this mounting process (in front of the mirror) until it is automatically correct all the time. Gun fit and consistent mounting are two huge issues that are rarely dealt with properly.
Just when you seem to have this taken care of, the "hunting clothes of the day" can change how the gun mounts. In additoin, if you think too much about lead, wind, feeling rushed and have little confidence....poor results are inevitable.
When I'm at the trap range most are shooting for a high score. When I shoot trap, I practice like I hunt. Using the gun I normally hunt with, I do not have the gun mounted until after saying "pull" and I do not always face in the exact direction the "pigeon" is expected to appear from. Practice getting the gun into the correct postion and looking at the "pigeon". Until this is accomplished, you will not really know where your gun is aimed. Practice until it just is!
For "swing" I start behind, under or over the target and swing in the correct direction based on the speed of the bird. The key is to "catch up" to the target while swinging. Practice swinging through the target faster than it is moving. Not all swings are the same speed. A second shot may find you thinking "catch up you fool". The third shot (automatic) usually means "see you later'. When I see the bird/clay pigeon and continue the barrel movement, I shoot (looking ONLY at the clay targert or bird). I do not track, "reach" a lead and hold it (ever). This evidently makes me more of an instinctive shooter. I can live with the results.
"Swing" is different depending on direction. Shooting for ducks or pheasants is usually "different". Ducks are more often than not passing shots or incoming. Pheasants are most often flying away (flushed). On an away shot, the usual error is shooting under/behind.
A properly mounted gun, learning how to "swing" based on the kind of bird and velocity in flight, practicing with different layers of hunting clothes and confidence need to be dealt with in that order. Then you have to think about your foot work.
Pheasants won't be dropping until you expect it to happen. Expectations are best established by following a plan not based on "a wing and a prayer".