*WARNING: under no circumstances do I take any responsibility for injuries. Never put any loop, noose, or other length of rope around your neck. This 'able is for educational purposes only!*
Step 1: The Necessities
Any length of rope, twine, yarn, or thread.
Step 2: Tying the Knot
Lay down your rope in an S formation as shown.
Next carry the bottom part over the length of rope
Begin looping the length you carried over, around itself
After making 5 or so loops, pull the remaining length of rope through the circle near the top.
Step 6: Pull!
Pull the loop tight by tugging on the noose and holding the knot. After pulled taut, the noose should be able to be adjusted.
Step 7: *optional*
You may now cut the remaining length of rope. Make certain you don't cut the wrong length.