I stand behind the ball and use my club to line up between the ball and target. Pick a blade of grass, discoloration etc, on the target line and close to the ball. Then without taking my eye off that blade of grass I step into the ball and take my setup. Trust my alignment (feet, hips and shoulders).
I must say that you're playing a nice track if you can't find anything to help with picking a target line. Cheers and good luck!