Here's how to make a wonderful(!) tie knob.
Visit this excellent site dedicated on this topic (french)

Step 1

The right part of the tie should be long enough to go as far as your knee, in fact it depends on you and the tie, try to find a mark.

Step 2

You must always turn around in the same way (here, I chose anti-clockwise).

Step 3


Step 4


Step 5


Step 6


Step 7


Step 8


Step 9


Here you are!

Nice uhh?

To get rid of it, simply hold the knob and pull the little end out.