As far as where a gun shoots for you, the low #7 on a skeet field is handy for that.
Watch where that target just starts to drop, which with no wind is usually just past mid-field, point and shoot just before it starts dropping. That's as near an aiming point as a flying target can be. It will give good feedback on point of impact (if there is one!).
Pattern size is easily seen on a splash board. We use a steel plate covered with white grease that's renewed with a paint roller.
Pattern quality is another matter. I've always shaken my head at the notion of 'holes' in a pattern. Sure, if you're shooting a stationary target like a turkey or the one in a hundred birds that truly have no relative motion, then an observed 'patchy' pattern is a problem. But... the target sees a cloud of shot, and a moving target experiences the cloud in 3 dimensions.
Brister came as close as anybody to demonstrating that with his towed targets.
What shows up on a pattern board isn't what a bird experiences.
Pattern size and point of impact are the variables we can control. We do that with choke, load selection, and a gun we can shoot well.
We're better at it than the rocket science boys have been lately.
