Butchers or Slip Knot
This is a simple knot used to tie up meat with twine or string.
Firstly make a loop and feed the twine back inside it.
Then pass the other end of the twine around the joint and through this loop.
Tighten the loop then pull the loose end through it.
The tightened loop should stop it lossenening.
Finally lock the knot with a simple knot.