My super complex, very complicated DIY underquilt project for the thread injection challenged:
Snag old unused sleeping bag from unsuspecting family member
Cut up four lengths of that apparently useless 550 cord that apparently must be replaced by amsteel, dyneema, zing lash something cause 550 is stretchy and under rated for counter balanced shearing forces of the inverse square of the hypotenused hanging triagnomic gravitational load constant function required when erecting any and all horizontally suspended human support mechanisms.
At least I was able to use the 550 for something...
Bunch up some fabric at each corner and larkhead'em
Hang the 4 strand from the ridgeline using tautline hitches or s biners or whatever, hop in the hammock and adjust as needed