I'm sure I'm not the 1st to think of this but I've not seen it posted here so thought I'd share.
I made a couple of hammocks for my kids. Very simple, just overhand knots at each end. I had intended to get around to making full woopie sling suspensions for them but haven't made the time yet. Instead, I have a couple of 15' ratchet straps I bought from harbor freight for cheap. I cut the hardware off and attached to each end of the hammock using the larks head knot. Wrap around the tree and tie it up using the ol' Henessey Hammock method. Works - simple and easy enough for my kids to do. But a REAL pain when it comes to adjusting height - untie, adjust, retie, assess, repeat.
Last week I took them out camping and had an idea that worked really well. I pulled the straps off the hammock. Each strap has a loop tied on one end - just like very long tree huggers.
1. wrap the strap around the tree like you would a regular tree hugger when doing the marlin spike hitch method.
2. at the loose end of the strap - at the height you want the hammock end, do the marlin spike hitch knot. But INSTEAD of putting a spike/toggle in it, throw the knotted end of the hammock in the knot.
3. If you need to adjust, pop the end out and redo the knot in the right spot. Throw a slippery half hitch over the marlin spike hitch to ensure it's locked in.
It's not as quickly adjustable as the whoopie sling method. But it's cheap, easy, light and quick to setup and adjust. I laid in it w/ my 260lb butt and it held just fine. I DID NOT sleep overnight in it. So I don't know if it would slip overnight or if it would make the knots impossible to undo. My assumption is that it would be just as strong and easy to undo as the normal marlin spike hitch method. Can't see why it wouldn't be.
Thought I'd throw it out as another alternative to a simple suspension method.