1. Bow tie
2. 5/8” Twill Tape or whatever you choose to use
4. Sewing machine or needle and thread
Step 1: Harvest the Clip
(Note: It isn’t worth using a seam ripper to take out the stitching. What you are left is a pretty mangled end.)
Put the clip to the side you will need it shortly.
Step 2: Prep End for Extension
Finally sew the tape into the end of the strap. I used a sewing machine and set the stich length as small as possible. There is no reason you couldn’t hand sew it if you don’t have access to a sewing machine.
Step 3: Reattach the Clip to the Extension
I then slide the clip to the middle of the adjustment area and cut off the tape 1" beyond the clip. Next fold about ½” of the tape over itself so the end is no longer exposed. Finally you need to sew the tape together.
The numbers in the adjustment area will no longer correspond to the true length so keep that in mind later when you are tying it.
Step 4: Done, Now Tie It Up
If you are looking to keep a lot of adjustment you might need to cut the strap back on the tie because once you sew the tape to the strap it will no longer fit through the clip. Also, I only wear full collared shirts so I don't have to worry about seeing that the extension doesn't match the rest of the tie.
I assume you already can tie a bow tie but for those who don't know how or need a refresher here is a link: http://youtu.be/VJv4Qh7zR3E