Had to do some research and also had another range day this morning at the farm. I use the classic weaver stance. I also grip the pistol in this way, thumbs to the left of the pistol pointing towards the target:
That's perfect and good enough for now. You will modify your stance when you get into the more advanced stuff, like shooting behind cover, both left and right.
The important thing is to know what it is that affects shot placement left and right, and what I described (hands and fingers touching grips) is 99% what causes it.
I'll give it a 'shot' when I go to the indoor range again
Yes, do it, it might seem strange at first, but you have a 99% chance that it will improve your placement left and right, and get them along the centre line through the bullseye. If it doesn't work, you will only have wasted 5 rounds.
Then, for the ups and downs: I'd advise three things:
1. Get rid of the red dot holographic sight, until you are hitting bulls consistently at 30m with iron sights. Red dot sights cannot improve on poor technique, and may exacerbate it. 2. Check your sight picture, high shots are sometimes either because you are struggling to see the sight at the end of the barrel, and then lifting it, so make sure you have adequate lighting (night shoots come later, or they are a result of anticipation, here your muscles are trying to move with the guns' recoil before it even goes off. To unlearn this, see next point on dry-fire.
3. With most of the low shots, it is anticipation, your muscles are tensing up and flinching to counteract the anticipated recoil. You need to unlearn this, and easiest way is to practice dry-fire. At home, every day, 4x per day. Find a safe place, and use an old casing / dummy round to protect the hammer, not sure if you get snap caps for the Glock. When you eventually go to the range, tell yourself that it's a dummy round in the chamber. You wont flinch. The shot going off will come as a surprise, and it will land where your front sight was pointing.
Good luck!
