I'm not a intuitive painter. Before I start I know exactly where it will end.
Here the hills got a shape by only painting the soil. I didn't touch the shoots yet.
Here the shoots got shape by lighten the top and darken the bottom.
The soil got some detail ...
The shoots got vertical stripes and the cut-offs got a core.
Then the shoots got some shadow on the left side to give them dimension. The cut-offs are detailed and a sign of life appeared at the horizon.
A detail: