To make field expedient cuffs, all you need are three zip ties.
Use one zip tie to secure the other two zip ties together as shown in the image below. You can also add additional zip ties and cut the ends to make points - this is done to prevent the wearer from using traditional zip tie breaking methods to escape. It's brutal, but effective. And if you are training to defeat criminal kidnappers, then it is in your interest to be able to think like them....
You can use small zip ties to make thumb cuffs.
Think about how you would escape if your thumbs were tied together with these kind of restraints. Always have an escape plan…