The following tips have grown out of the Elm Farm Boys vast experience at missing clays. This experience has been hard won, costly and garnered over many years, so save yourself the heart ache, and learn from our cock ups.
Needless to say the foundation of any good shooting career is a Browning or Miroku shotgun. Having got that sorted, you can move on to the more advanced levels of problem resolution.
Make sure you know your eye dominance and correct for it if needed. This is absolutely critical, if you are not 100% sure, have it checked by someone who knows what they are doing.
Gun fit. Make sure that you are looking centrally down the rib of your Browning or Miroku shotgun. With your head in a comfortable shooting position on the stock, and your body in a relaxed shooting stance, You need to see the two beads on the rib line up so that the mid bead occludes the lower half of the front bead. If you dont have two beads then get someone to look at you with the gun mounted to see that your eye is the right height in relationship to the rib. If your eye isn't in the correct relationship to the rib when the gun is mounted, then you are going to have to have adjustments made to the stock, or try another gun to see if that has a better fit.
Stance. Set your feet in the correct place in relationship to the break point of the clay. Make sure your body weight is oriented with more weight over your front foot. Make sure that your body is in neutral, when pointing at the break point, or the break zone. Experience will get you to the place where you can identify the best place to break the clay.
Establish your visual pick up point for the target; the point where you first see the clay as a clear and whole target, not just a blur as it leaves the trap arm. You can then set your best gun hold position, further along the clays flight path towards the break point/zone. and a little below it. You will also have established the point or 'zone' at which you plan to break the target. and with all those ducks in a row you are ready to call pull.
Now you need to execute one of the many methods for shooting clays.. The CPSA 'Method', maintained lead etc etc. Use whichever one you've been taught, and whichever best suits the target presentation.
Focus, (you'll practice your gun mount until you know that without looking at the beads your head is in the right place on the stock). You need to focus on that moving target so hard that it feels like you are trying the break the clay by the power of eyesight alone. A vague glance towards the target is not enough!
Keep your head on the stock Eyes on the target, head on the stock! Keep your head down on the stock until you have completed the shot and followed through, or swung on past the break point. Lift your head during the shot, and you change the precise geometry of your eye in relationship to the barrels and the barrels in relationship to the target. A great way to miss the target is to lift your head off the stock..
Get these right and you are most of the way towards breaking that target.. the only other variable is the lead you need to give it and that will come with experience as you learn to read the target.
Get into this routine for every shot, be consistent, dont get sloppy, and you will break clays. In short:
GET THE BASIC STUFF RIGHT EVERY TIME