My biggest problem is conditioning myself to line up the sights. I tend to want to point and shoot. I miss a lot that way, usually high.
If you can't find a range that allows holster draw or move and shoot -
Stand at low ready and bring your weapon up to your target, take the time to line up the sights. Do this several times shooting once each time. Try different distances. Then start double tap and do it again.
Another idea is with an UNLOADED gun, Airsoft gun or dummy gun, walk back and forth, sideways, forward, backwards with gun at low ready and periodically line your sights up on various 'targets' while you continue to move. You can do this in the privacy of your home, yard, basement or garage.
Lots of dry-firing.
This is by no means 'professional' advice, so take it as you will.