It doesn't always have to be about dropping the feed dogs and free motion stitching. The majority of the work done on this is straight line stitching.
I like make a quilt sandwich and stitch through all the layers.
First up is the choice of threads. I often choose a clear mono filament to stitch background elements moving to stronger, darker threads as I move toward the foreground.
The sky has also been done in mono filament (you could do this before adding the hills} to keep it far away, with just a little bit of free motion stitching around the moon!
The grasses are wavy but still done with straight line stitches and the feed dogs up.
Hope you have found this helpful.