Tsunagi can be rather tedious work if the maker chooses to keep tolerances  very close to the original.  Wood is removed and fit is constantly checked.  I prefer to keep the tolerances as close to perfect as possible. There is a tendency for tsunagi to be made less then perfect because they are generally inserted into koshirae saya and forgotton. Good koshirae deserves a good tsunagi and there should only be one level of work done (best level).   Ideally the tsunagi,  when place in its' respective shirasaya., should line up all edges as if the blade itself was inserted. 

The work is laid out

The sword is lined out

The piece is planed to outline

Work progresses

Habaki gets preliminary fitting

The wood is planed to thickness and shinogi cut in

The mune is cut in