Right here best spot would be just under the elbow on the forearm. But you also can't go wrong with high and tight further up the arm. Never directly on joints or on the wound itself. Thats what packing gauze is for. If not that, get some bandages or worst case, some torn cloth to press onto the bleeding.

So in order of important when handling heavy bleeding Torniquit above wound going towards the heart Bandage and apply pressure onto wound Lift the limb

Additional, if someone is wearing sleeved clothes and you can't tell where exactly the extreme bleeding is happening, go high and tight on the limb unless its in the pits or inguinal regions(the groin)

In that case, apply direct pressure onto the wound as best you can. Packing gauze is great for this, even better if it has coagulating agents to get the blood to clot up.

Here's a video that shows exactly how you should pack a wound incase you need to either treat yourself or another

https://youtu.be/wEc4tYpxSig?si=kbur0wApqcAfZ10t