I finished shaping a replacement handle for an old Disston saw today (there is more to come on this saw), only to face the challenge of drilling the holes for the saw bolts. Rather, as the drilling itself is a trivial matter, I should say the challenge of accurately matching the holes to those already in the blade.
Given the moderate rarity of this saw, enlarging the existing holes in the blade was not an option, so I needed to align the holes in the new handle with them very closely. Since the vast majority of my work is on new saws, this was a new problem, and one which had me staring into space for a few minutes.
After some thought, I came up with a solution which undoubtedly has been used by others, but which I have not yet seen described. Its chief advantage lies in being able to mark the holes while the handle is positioned on the blade. All that is required is a flat surface, a piece of tape, a square. And a pencil, which, despite a fascinating collection of mechanical pencils and leadholders, is invariably the single most difficult item to find in my shop. (I have seen your shop, and would argue that finding an unoccupied flat surface is the real challenge. -Ed.)