There are several Samisen loop knots, but I think this one is the best. This might not be the most efficient tie method, but I came up with it to make the process easy to remember. But even without trying for speed, it only takes around 15 seconds to tie and dress using this method.
Standing part to the right, free end to the left.
Frame 1. Cross hands, right palm lying on back of left hand. Grasp the rope with both hands where you want the knot to form. Uncross hands, right hand passing around in front of the left to form pretzel-looking overlapping bights. (Alternative, start with a 540 degree loop and push the legs together to displace the loop into two bights.) Hold the pretzel at the bottom in right hand.
Frame 2. Turn the pretzel into a Jack-o-Lantern by putting the free end through, in one "ear" and out the other, starting from the facing side (sequence: over-under, under-over). Double back and put the free end down through the "nose" (facing side). If you might want to increase the size of the loop, it is easiest if there is extra length in the tail, so set the tail length at this point.
Frame 3. Gather the "legs" of the loop and the free end (tail) in one hand, and the standing part in the other, and pull them apart to form the knot. The collar loop is the last part to form, and it will usually wind up being slightly oversized, so to dress the knot, pull the legs apart slightly to snug down the collar loop.
And that's it. The finished knot will have a (pretty--in my opinion) braided look from the front with the standing part forming a spine running down the back. Once this knot is snugged down, it strongly resists shaking apart when slack, can take many load-unload cycles, it can handle many cycles of spreading loads within the loop, as well as racking loads (alternating tension from one leg to the other), and pretty much any direction you pull it only makes it more snug. But no matter how snug it gets, it is always easy to untie. Just fold the collar loop forward (away from the spine), then pull the collar loop and spine apart. (Or push the standing part down into the collar loop.) I've even been able to untie one of these after it got wet and then froze. I seriously don't know why this knot isn't more popular. I hope an easy tie method might help to fix that.