This subject comes up quite a bit, and I am thinking about writing a short article about it. But the short summary of the article would be "have an experienced shooter shoot the gun."
The sights should not be adjusted until someone who can reliably shoot good groups has shot the gun. If you are not that person, then getting help is invaluable. Specifically, you need someone who can pick up any pistol and shoot a good group to the point of aim where the sights are set. A good group is something like 4" at 25 yards, and proportionately smaller at shorter distances. People who can shoot in this way are called target shooters, and you can usually find some at most clubs.
Giving shooting advice to someone who is not sure about their sights is not helpful. It takes a lot of practice to shoot well, and trying to learn and tweak the sights at the same time rarely works out well.
What really helps people shoot better is seeing someone good shoot their gun. If you are not sure about the sights, and then a good shooter shoots a tight and well centered group with your gun, then you get to continue practicing with confidence about what is going on. Having confidence in your sights, and knowing which shots were mistakes, is very important for developing skills.