That's where common sense enters the picture. Like has been said here already, pick a good tree, be aware of your surroundings, and don't be stupid.

My advice is more of how to keep safe while not ruining your hunt.

If it gets to a point where another hunter has gotten to an unsafe range I would give them a whistle first. If they continue I just tell them I'm there. No sudden movements or yelling. Just a simple "Hey".