Any wood can be used for a reflecting wall. If you’d like it to last, cut and stack green wood for your wall. The extra moisture of live wood will limit its flammability. If you’d like the wall to double as a firewood drying rack, you can build it from dead wood that is wet. Just pull out the sticks as they dry, throw them in the fire, and replace them with new wet pieces as you go. You could even use rotten wood to build your wall, if that’s all you have available. The bottom logs or poles that are closest to the fire will dry out and begin to burn first, unless you plaster them with mud, prop flat stones against them, or build the wall far enough away (about 1 yard) that it cannot burn. To build your wall, gather a pile of logs or poles, and drive two stout stakes into the ground. They should be closer together than the length of your shortest log. Set your thickest log on the ground, butted up against the two stakes, then drive in another pair of stakes to pin the log in place. If you plan a low reflecting wall, use stakes about a yard long and drive one foot into the ground. Go for longer stakes is you want a higher wall.