Doug Koenig talks about theI basics of sight alignment and sight picture.
The basics are:
Align the signs on the target, and don’t disturb them as you squeeze the trigger.
When sighting in you firearm, choose if you will hold the sights on the point of impact, or below he point of impact on the target. What ever you decide, you must be consistent.
Phage a watch to get the full details but please note, this is a US video so the link at the end, my not be relevant, but the info is still valuable.