Two of the things I recognized as being at issue with my follow-along painting from Marla Baggetta’s Sunsets in Pastel course are: my heavy touch (which led to “mud”) and my poor job at the underpainting.
The original picture is below on the right. To counteract the muddiness, I experimented with removing excess pastel in the ground area as well as the upper sky by using an inexpensive bristle brush.

The brush-off showed yet another problem — the underpainting which amounted to nothing more than a scribble. I should have done a wet wash, or a dry wash and not leave the scribbles!

That said, another thing was that I used the Blue Spruce NuPastel on Pastel Premier paper (320 grit); I had difficulty moving the hard pastel around.

So I decided to make a second attempt at the scene, being careful to keep a LIGHT touch.