The attached document shows how to make an "equal pull" MUAC strap from Brixton Health / VALID International Ltd. (and other) design MUAC straps using very cheap and readily available materials (i.e. an elastic band, a staple, and a ball-point pen - you will also need a marker pen for other designs).
The "equal pull" MUAC strap is useful in early training for demonstrating a "not to loose but not too tight" pull when taking MUAC measurements. Each trainee has an "equal pull" strap for the first hour or so of practical training. After that that we remove the elastic band just as a parent removes training wheels on a child's bicycle.
The document may be freely downloaded, copied, and distributed.