For a friendly match, there is an easy solution.
At the beginning of the match, you say, "Hey, Steve. See that tree limb? The rules say that it's a permanent fixture so whoever hit the ball into the tree loses the point. How do you want to handle it? Do you want to just ignore it and keep playing, or do you want to follow that rule?"
-- Random Error Generator, Version 4.0
-- Master Moonballer