Here goes at trying to explain a floating brace. In the upright post you drill a hole about the diameter of rebar, hole should go nearly all the way through, but not completely. Using another post or pole long enough that when the end is against the upright post at the height of the hole the pole is at about a 60 degree angle to the ground. What I do at this point is saw the end of the pole that is against the post so that the cut end is parallel with the post. Get a flat top rock and place it on the ground where the end of the pole is resting. Drill a hole in the upper end that will correspond with the hole in the post. Insert a piece of rebar through both holes. Set the end of the pole on the rock first. Notch the pole a couple of inches above the rock. Place a piece of wire around the post and the pole at the notches. Tighten the wire by twisting the same as you would on an H brace. Don't get it to tight or you will push the post over. It sounds much more complicated then it is, I just can't explain it any easier. USDA NRCS has pictures and and much better description in their fencing handout.