I want to learn how you index the pistol on target too...in that dumbed down fashion I was talking about.
Tangent time. I would like to address this because it is something I deal with frequently in taking "bullseye" shooters to "combat" shooters. And it seems to work quite well.

Lawrence I know you know "keep the finger off the trigger until the sights are on the target". Where does that naturally tend to place the pointing, trigger, finger? Just above the trigger guard running parallel to the bore. Where are the thumbs when one has a correct (for control) grip on the pistol? Both thumbs pointing forward parallel to the bore.

Now here is the magic: To "index" simply do what you have been doing all your life. Point. It doesn't matter if you have the handgun "high" or "low" or anywhere inbetween. It doesn't even matter if you are looking at what you index to. Just point your finger.

Try this; Keep your full visual focus on the computer screen. WITHOUT LOOKING point your finger at a lamp, or a TV, or a chair, or a cat (you get the idea) in the room. Now, look where you are pointing. Betcha a nickle you either pointed dead center, or pretty dang close.

"Indexing".

Now repeat that exercise using a thumb. I'll bet you are at least pretty dang close.

Now, think about your grip on the handgun again. You are indexing naturally with three fingers! Two thumbs and a pointing finger.

How in the heck could you miss ?!?!