When you walk up to a post for the first time, your feet will want to do the obvious thing: square your whole body to the trap house and face it head-on. It feels honest — that's where the clay comes from, so you point yourself at it. But squaring up hides a trap of its own, and it comes down to a fact that is easy to miss: the gun and your body do not point the same way.
The gun rides your shoulder, so your body is never square to the aim
A shotgun is fired from your shoulder, not from the centre of your chest. When you mount a gun, the stock sits into your strong-side shoulder pocket and your head leans over it. That means the barrel — the line the shot actually travels — sits off to that side of your body and angles back across toward the middle.
So there are two different directions in play every time you shoot: the way your hips and belt buckle face, and the way the gun points. If you stood perfectly square to the trap house and mounted, the gun wouldn't point at the house at all — it would sit canted off to your strong side, aimed at empty sky. Squaring your body up actually points the gun wrong. This is the whole reason a trap stance looks a little turned, a little sideways, and never straight-on.
You swing one way freely and fight the other
Here's the second half of it. Your body doesn't turn equally well in both directions. Picture a right-handed shooter. Turning to the left feels easy — you unwind, and your whole torso comes around smoothly with room to spare. Turning to the right is a different story: you have to wind up against yourself, and you run out of turn much sooner. A left-handed shooter is the exact mirror — the easy swing is to the right, and the tight, fighting swing is to the left.
That lopsided swing is the problem a stance has to solve. From most posts the trap can throw a clay hard to the left or hard to the right, and you don't know which until you call "pull" and the target is in the air. If you set up facing the middle, the birds that run to your hard side — right for a righty, left for a lefty — will run you clean out of swing before you catch them.
So you bias your stance toward your strong-hand corner
The fix is to pre-load the turn you're short on. Instead of facing the middle, a right-handed shooter sets the body and hips turned toward the right corner of the field; a left-handed shooter turns toward the left corner. You're borrowing turn from the easy direction and banking it toward the hard one, so that when a hard-side bird comes, you've already got the room to reach it.
And this is where the two directions come back together. Because the gun rides your shoulder and angles back across your body, turning your hips toward your strong-side corner swings the gun right back onto the middle of the spread. Body toward the corner, gun down the centre — the two offsets cancel, and everything lines up.
One method many coaches teach makes this easy to find on any post: stand with your feet about shoulder-width apart and your belt buckle pointed at the middle of the cone of angles for that post, then rotate your feet and hips about 45° toward your strong-side corner — a righty turns to the right, a lefty to the left. Treat that as a practical starting point, not a law carved in stone; the exact amount depends on you, and you'll refine it. But it puts your body where your swing wants it and your gun where the birds are, in one simple move.
Check it against the range's markers
A starting stance is a guess until you test it — and many ranges give you a ready-made way to check it right there on the post. Look down the field for the marking sticks (some ranges use other markers or reference features instead) that show the widest-left and widest-right angles the machine can throw. They mark the outer edges of the fan of birds you have to cover, which makes them a built-in test of your footing.
Set your feet as above, then test them without a live round anywhere near the gun. Keep the action open — no live ammo — hold the gun out in front of you with the muzzle pointed safely downrange, and swing it from one marker across to the other and back. You don't even need to mount for this: just watch the muzzle track across from the left marker to the right marker. If it travels the whole way freely, your stance covers the field. But if it drags, or your body runs out of turn before the muzzle reaches a marker — especially on your hard side — then you haven't banked enough turn toward your corner. Re-foot a touch further toward your strong-hand corner and run the check again, until the muzzle comes free all the way from edge to edge.
Aim for a little room to spare, not a maximal reach. A stance that only barely gets the muzzle to the outer marker will come up a hair short under the pressure of a real target. Set your feet so both markers come free with turn left over, and every angle in between takes care of itself.
This is the same truth the move and check your mount drill grooves: a mount that holds true straight ahead can quietly fall apart once you turn the gun to chase a wide angle. And each post needs its own foot check for the reason laid out in the trap field post by post — every post sees a different slice of the machine's cone, so a stance that frees the swing on one post can fight it on the next.
When you're happy with where your feet are pointed, the next thing to settle is where the muzzle waits before you call — that's where to hold on each post, the companion to this one. Feet first, then the hold; together they decide how short and how calm your swing to the bird gets to be.