I used to pull mine good and tight, I guess I thought that was needed to stay high enough off the ground. But I think it say on the HH stuff sack something like " pull moderately tight". That is about all there is to it, not complicated. Once your ridgeline is straight, that is probably about right. If you get in and the RL is guitar string tight, you probably need to loosen it just a bit.
If I get in and the Ridgeline is nice and straight and keeping the net well away from my face- but NOT guitar string tight- that is probably about right. A little tighter or looser is probably OK also. The straight RL sets the correct hang angle.
As zukiguy said, too tight puts a lot of extra stress on suspension and trees. And back in my tighter is better days, I discovered that it was actually posible to stretch the RL when using a Hitchcraft device and probably with cinch buckles and rings. Tight enough to cause an obvious decrease in comfort. And some folks have snapped RLs by getting too aggressive.
While playing and experimenting, you could also start in reverse. Start out with a bit of sag in the RL. Get in and see if it is then straight and the net well controlled. If there is still some sag, get out and tighten up a little more until the line is nice and straight as you lay down but you can still easily move it with your fingers, and it seems comfy. Then after you do this a few times, you will know the feel of exactly how tight to pull the suspension when you set up. But the suspension tension does not have to be real precise. As long as you don't get gung ho and really put your weight/muscle into it!
Though there are probably folks who still like to go that route.
I was surprised to see how it was actually easier to stay high enough off the ground by hanging more loose and with the huggers higher on the trees.