I learned this knot from the now defunct Knotworkn website. The ends can be trimmed close to the knot as shown. Or you can leave the ends uncut and have two ends to tie together for a fourth loop
Fold cord in half. At the point you want to make your top loop bring top strand over and under itself. Then bring that end over and under to complete thumb knot
Bring lower strand under the upper strand and up through loop. Then bring the end down through thumb knot. You can see the MWK developing
Take the lower strand and bring it up through the thumb forming one of the lower loops. Then bring that end around as shown to form the third strand of the MWK. You can stop at this point and tighten the knot for a lanyard with one loop at each side of knot.
Do the same two steps with the remaining strand. Now all four bights of the MWK are visible
Now comes the tedious part. Tightening a MWK can be a bear. Here is how I did it. Take the lower strand as it emerges from the thumb knot and tighten it slightly moving it to the right. Do the same with the second strand
Now I take the two strands in my right hand and the two loops in my left. I twist my right hand clockwise and my left hand counter-clockwise while,pulling my hands apart to tighten the knot. Now is the time to move a strand to the left or right so it falls in the proper sequence. One at a time pull on each cord an it emerges from the knot on either sade.