A wire support leading to the ground is what I use, like #9 wire. I'm open to ideas to, but haven't found a better way.
Old aluminum arrows or carbon arrows or the stabilizing rods In your old pop up blinds. Or get some 3/16ths rod cut them about 20" long and weld on a washer about 3" up from the end so when you drive the support In to the ground It won't spin.
Drill a hole through the rod or arrow up near the top shove your sport wire through that hole and then bend It down and wrap it In place with some tape. If you have problems drilling that small hole through the steel rod just take a hammer and flatten It out a bit.
Leave about 10" of wire sticking out from the rod. Drive the support rod about 3" into the ground. I haven't seen a better way of adjusting my loop then with this system Bend the wire up or down to adjust height. Bend the wire back and forth to adjust to the angle of the trail. If the trail Is going up or down you can adjust the loop so It's at the same angle as the trail.
And wind won't effect this system and In some cases I have had deer walk right through the set up and have the loop swing right back Into place.
When you make a catch the first go around will either knock the rod over or If It's frozen Into the ground It will bend It right over.
My stabilizer's are bit more sophisticated. Mine are 1/4" square stock and I have a hole and a slot lazar cut Into the support. Two holes would make It tough to get the wire bent just right but the slot gives me a better chance to get the wire though both openings. This way I don't have to wrap the tag end of the wire with tape to hold It In place.
And with the steel stabilizer supports I don't have that tangled up mess you have with wire supports.