Start with the line where rocks meet the water. Then where the sky meets the mountain. Then look and see if you want to add more.

Thank you! I am going to use a warm and natural batting as that is the one I really like to use. I also have a Legacy 80/20 which is quite thin so I was wondering if this would be ok as it is a wall hanging and I do not need the warmth. I really appreciate the advice on where to start too as I really had no idea and would have just started at the top and worked my way down! lol
Vines and leaves are a wonderful idea for the borders too, and also just highlighting things/animals. Thank you all for taking the time to help me. I will post photos when I have summoned up the courage to put it on the frame!