Our first plan is to use a proven commercially available tourniquet. Barring that, an improvised tourniquet using a cravat, or a strip of fabric, with a windlass for leverage. Given no other choices, you can may be able to use the casualty's clothing with a rigid windlass, such as a metal pen, kitchen utensil, small tool, etc, to make a wearable improvised tourniquet. This is verified effective with doppler ultrasound.
