This is my method...
What does it require? A lot of time.
I sell them when I have one on hand but I haven't made one in years. The cost was equal to someone buying a dremel, a hot glue gun, and a bench vise. ($50.00 +/-)
I still can't believe it took me so long to realize that was a common difference.
Also remember most of the time you should plan on "thinning" the 60 pin Famicom pass-through since stock it's a little thick and you may have issues getting all Famicom cartridges to fit on it.