Tourniquets have become ubiquitous tools for controlling hemorrhage in the modern prehospital environment, and while commercial products are preferable, improvised tourniquets play an important role when commercial options are not available. A properly constructed improvised tourniquet can be highly effective provided the user adheres to certain principles. This review article identifies key skills in the construction and application of improvised tourniquets on an extremity. An improvised tourniquet design for an extremity should include three components: a strap, a rod, and a securing mechanism. The strap can be made from a variety of materials, but cravat- like fabric has been shown to work well. Optimal strap dimensions should be at least 2cm in width and a continuous segment long enough to extend around the extremity while still offering ends to accommodate and secure the rod. The rod should be constructed from a material that is hard, strong, and capable of withstanding the torque placed on it without bending or breaking. After torque is applied, the rod must be secured into position to maintain the constricting force and survive patient transport. Finally, the need for an improvised tourniquet is a contingency that all first responders should anticipate. Hands-on training should be conducted routinely in conjunction with other first responder tasks.