Mate.. in all honesty its all trial and error.. ive made lost of mistakes over the years and refined my technique over and over... i have a good system now that allows what already exists to still remain while restoring... gentle steps and whispers.
What ive learnt, ive shared, hence my restore threads.... vectorising text to suit, cutting in stencil and weeding out the unecessary is the trickiest part but the rest of it anyone can do so long as they know how.. anyone could do this io be honest