Drill longitudinal hole in front edge of component.
Slide in angled dowel, position template and drill lateral hole in the surface.
Apply glue to one side of angled dowel, slide on counterpiece and tighten.
The angled dowel can be screw-fixed with cross dowels at both sides for completely separable connections or to readjust the mitre.
The mitre can also be glued, e.g. during installation, by pulling the components together using the cross dowel.