There is another way I should tell you about which involves removing plaster and doesnt sink the architrave below the level of the wall surface .
It does however mean the skirting meets the architave not quite flat.If you set the architrave on the door lining set in 4to6mm from the edge and draw a line down the plaster. You then taper the plaster from the opening side of the line to the lining. This cocks the architrave at a slight angle to the wall surface.Ive done it several times and its not that noticeable
It does however mean the skirting meets the architave not quite flat.If you set the architrave on the door lining set in 4to6mm from the edge and draw a line down the plaster. You then taper the plaster from the opening side of the line to the lining. This cocks the architrave at a slight angle to the wall surface.Ive done it several times and its not that noticeable