Regarding the installation and initial regulation of pistol sights. I have found that if the sights are installed as precisely centered as possible very little adjustment is subsequently required.
On a pistol like a Glock I use a machinist's ruler to verify there is no skew in the sight blade relative to the long axis of the slide. (9 times out of 10 when I see someone's Glock where the rear sight is not centered for proper zero the front sight is skewed.) I lay the straight edge against the side of the front sight and I look for the other edge of the ruler to be parallel with the slide. If the front sight is centered, parallel to the slide and the rear sight is centered rarely if ever have I found a pistol that needed windage adjustments.