Proverbs1423 created the topic: Best Bow or Gun Treestand hoist
Instead of a standard 15 or 20 foot length of rope or cord, consider using cheap retractable animal leash. One of these can be purchased online and simply zip-tied to your treestand.
Note: You can also mark the string with whiteout or white paint every 5 or 10 feet to give yourself a real idea of your treestand height.