I normally just tie a rope to 2 samplings and throw a 6 x 8 tarp over it in an A frame or leanto then either tie the corners to other saplings or bushes or stake them out to the ground.
If no trees, I use a couple tent poles and stake the tarp out in an A frame. Another thing I will do is tie a rope to the center of the rear bumper and tie the other end to something near by, tie 2 ends of the tarp to the opposite ends of the bumper and stake out the other 2 corners. In all cases I make it high enough to crouch under it to put gas in, check the oil & pull start it.
