I have sleep apnea and require a CPAP machine to sleep with. Here is a DIY harness I made to hang my machine while I sleep. I will hang the battery for it separately.
The base is a tray from a small electric "toaster" oven. I drilled holes in the four corners. The I cut 2 pieces of rope, inserted each end in a hole on the same side, then tied a stopper knot (figure eight) to prevent the rope from slipping through the holes. That gave me a loop of rope on the front side and the back side. I was careful to make the loops as close to the same size as possible so it would be level front to back. I checked this with a level to make sure. Then I used the level and found what point on both loops would make it level side to side. I inserted another short piece of rope through the rope loops, perpendicular to the rope (skewered it), and wrapped around twice (once on each side of the skewer, in opposite directions) then tied an overhand knot on top. Then I finished making a small loop with the short piece, connecting the ends with a square knot.
P.S. The reason for making sure it stays level is because there is a humidifier tank on the bottom (the blue part) that has air pass over it. The tank needs to be level.