A simple jig to assist spooling new ribbon from Baco Ribbons.  Two spool edges should be printed, and one winding base.  You'll need a standard 608 bearing to go in at least one side of the spool edges for the spool to smoothly rotate on. (This probably is not necessary, but I had some 608's lying around.  If you wanted to not use this, it will still work, just not as nicely)  

To use:

Lay the base on a good flat sturdy surface, push fit the spool edges onto either side of the spool of ribbon.  This also helps to keep it nicely spooled up so it doesn't fall off the roll.  Place the 608 bearing on the post and attach the ribbon to one empty spool.  Use your finger to load as much ribbon onto the typewriter spool as you want, and cut when done.  Then attach the other side of the ribbon to a second typewriter spool.  If you have an eyelet setter, you can put eyelets to auto reverse on typewriters that have that functionality.  

It's not fancy, but it works. :]