A softer feel really works for this picture I think. It would have been stronger in composition with a different crop taking out the very right tree and just leaving three of the dark trees on the left. This would have showcased the lighting of the sky and the tree in the middle nicely I think.
Unfortunately, there is insufficient landscape detail in your image to see, which leaves skyscape. As such, perhaps more contrast in the sky would add some drama or interest for the viewer.
Great job shooting for the sunset sky! In doing so the details of the remainder of the photo are lost. Some things that I see to improve upon are getting that horizon line in the bottom third, it is a little lower than that right now. Also there is no foreground or mid ground here, it's all background.
more detail in the land area would help this along. I like the silhouette of the tree in the center of the shot, however I think it would have more impact if it were to the side of the shot. Good luck :)