"The constrictor knot is a way of making a secure, temporary or semi-permanent binding (it’s a good temporary whipping for a rope, closing a bag, or holding a punch of poles together.)" here's my video on this knot with a no-tangle paracord skein
Ultimate Knots The Non Slip Loop Knot. The strongest loop knot you can tie. Used by big game anglers worldwide. Easy to tie, far stronger and more reliable than the old fashioned strangulating figure eight knot that can substantially weaken line.