You know you have the right LZ clearing when you approach from the southwest, and see 3 soldiers standing at the northeast edge of the LZ.
It looks impossible at first, I crashed over and over trying to get in that LZ. So I practiced landing in much larger clearings, and saw that I was landing short, and hitting trees with the tail rotor. I practiced in progressively smaller clearings until I had the right sight picture.
Also, Reflected told me to turn my Gamma up, and the extra brightness really helped to see the LZ.