To the direct question, as indicated in other answers, tourniquets are placed towards the torso from the site of injury.
There's been a major initiative in the US known as "Stop the Bleed." You'll find a significant number of authoritative trainings and recommendations, including the use of tourniquets.
Other answers mention the risk of complications with the tourniquet both in tissue damage from prolonged usage as well as Compartment Syndrome upon release. Considering how long it will be to reach extended medical care is part of the equation that's beyond the immediate question. "The Great Outdoors" includes back country where it may be several days to care, or a quick trip down the hill, the car, and a freeway to a trauma unit - or even a helicopter rescue.
There are a number of other suggestions on the thread such as elevation that are situationally dependent on the method of injury and possibility of other injuries. They may not be appropriate in all cases. For instance, a torso injury related to a fall in The Great Outdoors might be combined with an extremity bleed where elevation may exacerbate the combined injuries.
In the US, there are in-person trainings that include pressure point usage including (but not limited to): Stop the Bleed, general First Aid (often including CPR), Wilderness First Responder, and Community Emergency Response Team (CERT) sections on medical response.
The Wikipedia article on tourniquets is well written: https://en.wikipedia.org/wiki/Tourniquet
Please note: I'm not a doctor, and this shouldn't be construed as authoritative medical advice. I recommend the "Stop the Bleed" links and resources mentioned over any unattributed advice in my or other answers.