>>1417550pretty clever solution anon. let me set you up with some timestamped links for the knots in case you get bored sometime.
try using a bowline loop for the end and toggle it with a stick to either the tree or the tarp like pic rel for very quick setup and teardown esp if you leave the bowline in the end of the rope for future use.
https://youtu.be/Q9NqGd7464U?t=34taut line hitch on the other end
https://youtu.be/H4rbBHp1QXo?t=49if you really want to crank tension into that shit use this trucker hitch with an alpine butterfly loop
https://youtu.be/Gkepmm-5pNQ?t=32here is a simpler way of doing the alpine butterfly
https://youtu.be/n2aRj8dQPRQ?t=27 