Couple of years ago I tried a IWB holster, and liked it. It did have one problem: the grip sits low and tight enough to the body that I had trouble getting a ‘correct’ grip. Which caused accuracy and control problems. I tried working it out, but I just could not get that correct grip. So one evening I loaded up snap caps for some practice and started over, working some different angles to see what might work, and finally hit a combination that did.
Technically, it would be considered very bad form as the general rule is ‘Get a firm grasp on the grip before you begin to draw the pistol from the holster’; and I don’t do that.
I just had time to practice this a bit and remind myself of the proper description: the thumb slides down the inside of the grip just at the bottom of the beavertail but isn't doing anything but positioning at this point; it has the web of the hand at the tip of the tail curve. The second, third and fourth fingers just hook around the front of the grip at the middle joint and start the actual draw. As the piece lifts from the holster those fingers tighten and that pulls the grip solidly into the palm in proper position with the fingers well wrapped around. While that's happening and the piece is tilting forward the thumb angles up, not on the safety but getting there. About the time the piece is coming level the thumb has risen high enough to engage the safety, ready to push it off.
When I wrote the original description it was late, and I was tired enough my eyes were fuzzing; apologies for a lousy description.
(end of update)
Once I had that motion figured out, I did a LOT of dry-fire draws getting it locked in. Then at the range with ammo, with both .45 and .22(with the conversion kit on) to make sure it worked. And it did. So I tried it more, drawing from all kinds of angles- square to the target, angled left, angled right, back to the target & drawing and turning, dry-fire first and then at the range. And it does the job for me.
Big factor, passed on a long time ago from Capt. Combs: start slow, get all the motions worked out and locked in, then speed up a bit. And so on.
That's not the best description of how I came to this; but it's late, my eyes are fuzzing and I'll pretty it up later.
Added: When I first learned handguns, it was all from an exposed holster, not concealed; the grip was right out there where you could place your hand before you actually moved the piece. Later, the first CC holsters I used were tighter to the body, but still made it easy to get the grip just right before you actually drew. However, that meant they were a bit- compared to the IWB holster, sometimes a lot- more difficult to conceal. I really like the IWB: it keeps the piece tight to the body and doesn't shift, which aids concealment and means the grip will be right there every time; one of the holsters I previously used tended to slip back & forth a bit, which caused problems. But using the IWB well meant a change in method. Thus this post.