Setting up a hammock rain fly is only slightly more complicated that setting up the hammock itself, which is a stunningly easy process. Almost all hammock flies rely on the same two hanging points as the hammock, which is usually a pair of trees. By attaching each end of the fly to those same trees, only a few feet above, the main tension line is established.
Then, additional grommets or connectors around the hammock can be secured laterally, either to the ground or to other trees. This creates the perfect slope for the shelter, as rain water will just drip off the sides before it has a chance to soak into the material.