Couching is simply sewing a heavy thread in place with a finer thread. Its a retro technique, too, that was originally done by hand, but it works beautifully by machine as well. I use a zigzag stitch to secure the heavy thread in place.
DIY Simple Backyard Shade - Put PVC pipe into bucket then pour cement around it. Once dry, put bucket in tall planter, surround bucket w/ gravel, top w/ soil. (Not covering pipe) Stick bamboo pole into pipe & hang fabric w/ ties through grommets.