Knots for towing

If the overriding consideration is ease of untying, a simple Timber Hitch will be an obvious contender:

https://notableknotindex.webs.com/timberhitch.html

The Sailor’s Hitch (ABoK 1688) also unties reliably:

https://notableknotindex.webs.com/sailorhitches.html

And there are friction-based load-shedding strategies that can be used to reduce loads on other hitches, such as seen in the third diagram here:

https://notableknotindex.webs.com/slippedbuntline.html