It's easy to buy hardware to attach to a lanyard that will break away if snagged accidentally. My work requires that I wear an ID badge around my neck, and my employer supplies simple neck lanyards with plastic break-away clasps.
That's OK...I guess. I'd much prefer a solution that is cord only, using a break-away knot. A search of the internet didn't yield exactly what I was searching for, so I tried my own design.
Here's how I did it.
Step 1: Start with about 60 inches of cord.
I used 1/8-inch diameter cord, similar to paracord, but a bit more stiff. Paracord would probably work even better.