You will need to get a spool of serving thread.
Tie off to one end of something solid on your bow.
Now,
just keep going around and around and around.
Now,
after you have about say 1-inch of serving....
Make a horseshoe shape
First leg of horseshoe
Hang onto the top of the horseshoe
now,
run the ball of thread (or serving tool)
in the same direction around and around and around,
but go UNDER the horseshoe...
Notice...,
when I was initially wrapping around and around and around...
the serving was GROWING LONGER to the left...
and
when I continued wrapping around and around and around,
UNDER THE HORSESHOE..
the serving is GROWING TO THE RIGHT...under the horseshoe..
notice,
the big ball of "thread" is off to the right, sitting on my workbench
I am still holding open the "horseshoe"...
now,
I WRAP the HORSESHOE
around and around and around the bowstring...
Notice how the HORSESHOE is getting smaller and smaller...
keep wrapping the horseshoe around and around and around..until...
you reach the end...
now,
just PULL the long string of thread
and the horseshoe will completely disappear.