I think the natural look has a focal point of 1.67:1. I'll never find the information agin, but the center piece needs to be offset .67. Good luck with that one.
There are also natural shapes. U, where both the left and right sides are raised and the center is low, just like the letter. n, where the center is is raised and the sided are low, again like the letter. Triangle, where the left or right is high and the landscape slopes to the right or left.
No straight line will help you get the natural look.
Then there's the best look of complete randomness.