A Woodworker’s Notebook: Adjusting a Metal Plane

Tightly screw the cap iron (About Cap-Irons) to the iron with an edge distance of 1mm - 1.5mm. If you have a fine shaving aperture, the distance is not as important as is sometimes made out.
Lower the blade into place, avoiding contact with the plane body.
Jiggle the lateral adjuster to ensure that it has correctly located with the iron.
Fix the lever cap. It should be as tight as possible, but not so tight that it cannot be released with an unaided finger under the cam's lever.
Rest the heel against a light-coloured surface.
Follow the stages 1 - 4 below.
Test on the kind of wood you are going to use.
You can increase insufficient set, but to reduce the set, start again at stage 3.

Sight down the plane and find the edge by waggling the lateral lever - which probably will be necessary in any event.
Adjust so that the cambered edge is centrally disposed
Wind the blade backwards until the edge just disappears from view.
Wind it forwards again until just visible.

Note:Some improvers have difficulty in knowing what to look for when sighting the plane. This is not surprising considering that one is looking for a dark line of only a hair's thickness in the mouth area. One tip is to form a background for the sighting by painting the back lip of the mouth white.