Here is how to make a set of handcuffs with a shoelace. The shoelace is white, it shows up well on my Wife's back:
1) Just stretch out shoelace horizontally.
2) Bring ends up & around to make loops. Note that right side is on top of horizontal piece, left side is underneath.
3) Tuck right side vertical piece underneath left side vertical piece.
4) Pull the (old) right middle side up and through the original left loop. SImultaneously, bring the original left middle side down and through the right hand loop.
 Step 1
|  Right side on top, left underneath
|  Right underneath left
|  Pull each thru the other loop
|
Old Enough to know better...but I don't!