[yardshop]

Or tie it as a double round-turn bowline, with an extra turn for both the "rabbit" going around the tree, and for the hole.

In a previous job I had to constantly take my office master key out of my pocket and put it back. Before long I made a lanyard for it with a brass clip to go on a belt loop and a regular split ring on the other end, both attached with a normal bowline. After a short period, maybe a few weeks to a month, I noticed it loosening up. I retied it with double round-turn bowlines on each end, and it held together like that for years.