For general knowledge, consider that applying a tourniquet is meant to (and needs to) cut off all circulation beyond that point. Unless a medical facility is reasonably close, there is a good chance the recipient will be losing that limb. Obviously better than dying, but I want to make that clear for anybody who may consider applying one someday.
Making a tourniquet from what you have: you need a thin strong stick (a pen will usually do), and a length of cloth (triangle bandage, or ripped clothing in a bind).
Wrap the length of cloth above the joint nearest the bleed (or nearest the shoulder or hip if applicable) and twist the cloth once; no knot, just one twist. Lay your rod (heh heh) over the twist (I like a half-hitch, but it's not specifically necessary), and then do another of the same over the top of the rod. Turn the rod (tightening the cloth). Stop turning AS SOON as the bloodflow from the wound is no longer significant.
What's "significant?" 1 liter of blood loss in an adult is a lot, but not specifically dangerous. 2 liters is VERY dangerous, depending on size; more for bigger people , less for smaller. Use that as your guide.
Always apply direct pressure to the wound first; elevate the wound above the heart; only apply tourniquet if those things don't work.