I'll offer a few thoughts, in no particular order:
1. Stance: As mentioned, it seems to be personal. For me, isosceles works well. The push/pull thing has never worked for me. To be accurate, you have to be consistent from shot to shot, and I find it's tough to push & pull with exactly the same consistency between shots. For me, an isosceles stance with a neutral grip works well. Imagine your 2-handed grip holding a piece of paper, such that the paper is held firmly, but doesn't rip. Again, though, experiment, but keep in mind that what works for you is best.
2. Target: Decide what form of shooting you'll be practicing, then practice it, and use an appropriate target. If you're going to work on your marksmanship, you might use an NRA B-4 target, for example. I included a link to a few you can simply print. Don't place a silhouette at 25 yards, then try to shoot nice tight groups.
http://dotclue.org/targets
3. Front sight: You've probably heard this before, but it bears repeating -
Watch your front sight. At all times. Ask yourself if you watched it with undivided attention. Did you just
think you were watching it just because the target was blurry? Maybe you just weren't looking at anything at all. Did you watch it during recoil? What did it do? How was your sight alignment the
instant the trigger broke? If you know, you'd already know where the shot hit (that's why the target ironically really doesn't matter and why dry fire is so powerful).
4. Peaking: Related to point #3. Do NOT "peak" at the target between shots. This is surprisingly difficult to avoid. Just grip and raise the gun, obtain a good sight picture, focus on the front sight, and take aimed deliberate shots. If you're peaking at the target in between shots, you're taking your concentration off the front sight.
Watch your front sight. At all times. If you peak, you're also likely to adjust your grip, and/or lower the gun. For these reasons, peaking at the target is a real accuracy killer. If you're using Shoot-NC targets, I suggest you don't - the temptation to peak is just too high.
5. Dry fire at home often. Whether you're practicing combat action type shooting, or working on your marksmanship, most of what you need to practice can be practiced at home via dry fire. Range visits are fun, but I also use them to evaluate how well I've been practicing at home. If I haven't been practicing at home, I'm not as motivated to get to the range. For accuracy work at home, tape up a target, aim and just dry fire while focusing on the front sight and trigger control. A good air pistol is helpful, too.
6. Charts: Others may disagree, but I've never thought much of those diagnostic charts. Your front sight tells you everything you need to know, but you just have to watch it.
7. Accuracy during rapid fire:
Watch your front sight. At all times. Not trying to be funny here, but accuracy radically falls off as you shoot faster because you stop really aiming. I recall Brian Enos, the great practical shooter, wrote on his forum that you can never get around the fundamentals (sight picture & trigger control), but that you just apply them faster. A good double tap, then, isn't just pulling the trigger twice as fast as possible - it's 2 separate aimed shots in succession.
8. There's some good (and not-so-good) on-line reading available. There are some good books, too. A couple of the best include the USAMU Manual and A Pistol Shooter's Treasury. You can probably find a free pdf copy of the AMU manual on-line somewhere. I know individual chapters are available at bullseyepistol.com, which is also chocked full of good info.
