I used a tutorial that holster maker Will Ghormley had/has on his website:
http://www.willghormley-maker.com/MakingHOGRig2.html" onclick="window.open(this.href);return false;
You
can glue the plug into place and then stitch it if you want, I found I didn't need to when making mine. When it comes to sewing it up, if you don't have a leatherworking awl,
WAIT until you do. I'm not talking about a lock-stitch awl, one with a spool attached; just a plain, old, diamond-shaped, awl. (I exclusively use diamond punches to make the stitch holes on my work and then saddle stitch everything I sew. I do not use a lock-stitch awl.)
Drilling out the stitch holes with a drill looks (to me) awful. I made the stitching holes on my holster plug using a drill, and on the other one, I used an awl to form the stitching holes. The second one looked
so much better. Granted I had practice by making mine, but the awl allows for MUCH more precise placement of the holes. It makes a major difference.