This article by Dennis Santiago has many good points. But for me, one stands out far above the others.
In his paragraph titled Slow Fire Offhand is buried this phrase: “Just focus on the reticle.” Next is “trust your wobble,” which seems the main theme of that section. But I want to emphasize the first phrase. Why? Because it represents a central theme to all small arms marksmanship: if you want to hit the target, don’t look at the target; instead “focus on the front sight.” With iron sights, this is a simple concept. But with a scope, where both the reticle and the target are in the same focal plane, it’s not so simple. But the truth is, if you let your mental focus drift from the reticle to the target, you’ll doubtless also let the reticle drift from the target.
OK, now to the second point: wobble area. As Mr. Santiago says, “That wobble was always there even with iron sights; you just could not see it before and it’s plain as day to see now.” Here’s an extreme example. I have a friend of some 20 years who has a serious tremor; he’s had it as long as I’ve known him. When we met, he didn’t think he’d be able to shoot a pistol. It told him: “Ignore it! Just shoot through the shake.” He did and he does fine. Why? Because his wobble area is always somewhere on the target, and of course it centers on the X-ring.
The third point is about Zen/Taoist magic. Mr. Santiago says, “[S]queeze with the best trigger discipline you can muster and crack it when your ‘chi’ says TEN!” Chi (or Qi) is “the energy flow or life force that is said to pervade all things” and produce “balance and harmony.”* But to me, relative to shooting, what is described here is a magical relation between eye and finger that seems to avoid the brain … instead, as I tried to hold my wobble area somewhere near center, my rifle would magically go off. That magic didn’t happen often, and when it did it was the product of hours and hours of dry fire medication; but it did occasionally invade my shooting. And it’s truly magic.
Army Reserve Marksman 
This article by Dennis Santiago has many good points. But for me, one stands out far above the others.
In his paragraph titled Slow Fire Offhand is buried this phrase: “Just focus on the reticle.” Next is “trust your wobble,” which seems the main theme of that section. But I want to emphasize the first phrase. Why? Because it represents a central theme to all small arms marksmanship: if you want to hit the target, don’t look at the target; instead “focus on the front sight.” With iron sights, this is a simple concept. But with a scope, where both the reticle and the target are in the same focal plane, it’s not so simple. But the truth is, if you let your mental focus drift from the reticle to the target, you’ll doubtless also let the reticle drift from the target.
OK, now to the second point: wobble area. As Mr. Santiago says, “That wobble was always there even with iron sights; you just could not see it before and it’s plain as day to see now.” Here’s an extreme example. I have a friend of some 20 years who has a serious tremor; he’s had it as long as I’ve known him. When we met, he didn’t think he’d be able to shoot a pistol. It told him: “Ignore it! Just shoot through the shake.” He did and he does fine. Why? Because his wobble area is always somewhere on the target, and of course it centers on the X-ring.
The third point is about Zen/Taoist magic. Mr. Santiago says, “[S]queeze with the best trigger discipline you can muster and crack it when your ‘chi’ says TEN!” Chi (or Qi) is “the energy flow or life force that is said to pervade all things” and produce “balance and harmony.”* But to me, relative to shooting, what is described here is a magical relation between eye and finger that seems to avoid the brain … instead, as I tried to hold my wobble area somewhere near center, my rifle would magically go off. That magic didn’t happen often, and when it did it was the product of hours and hours of dry fire medication; but it did occasionally invade my shooting. And it’s truly magic.
* http://www.religionfacts.com/chi