Starting with the spiral configuration, two half-hitches would seem reasonable. When hanging bear bags (think heavy) for the night, I used a Kellick hitch (half hitches or marline hitch, and then a timber hitch).
BTW, some tips, if hanging something heavy between trees well above your head, place your rope 5 to 10 feet (more if spacing of trees is large) higher than you want your item (usually placed by throwing the end of the rope tied to a rock over a limb). A higher placement will dramatically decrease the tension you will need to exert to lift and anchor. For those who remember their physics, yep, its that tangent of the angle trig thing which makes getting that last bit of height impossible (tension needed approaches infinity). If you want to go pro, a pulley tied in the rope where you want your item and where the pulley has been prethreaded with a second rope for the lifting of the item makes hanging heavy items a snap. Secure the main line, hoist your load, tie off the load line (and its reusable for multiple nights/meals etc!)
DDK