First image when you click the flag is mine (it's a redraw btw); click/space to view @potatobear616's original! Credit to @potatobear616 for the original concept and artwork :D This is mostly just for the background, but I had to re-do the girl because it would have looked really strange otherwise (I was painting on top of the original so the drawing was getting covered up; I decided to just hide it and redraw the character). you can look at her if you want, of course! but I will only comment on the background :)
To make the background of the mountains look farther away, I made it a lot closer to the color of the sky, which gives it a faded look! I also gave a bit more depth by adding several layers of the flowers, with the ones farther back being fainter and less detailed. I made the sky color slightly less saturated, and I added some different colors with a soft brush too so it wasn't just one color (also made it a bit lighter towards the bottom). I actually moved the placement of stars farther from the moon, because the moon light tends to obscure stars nearby (even when there's just a bit showing). Uh I actually forgot to add the glow around the moon, though! Also, I curved the main "line" that the stars were placed along so they passed through the girl's head, pulling attention toward the center. Lastly, I added a couple of flower silhouettes in the foreground using a glow layer to make it look like the flowers also continue in front of her! That's just a little touch. I often find myself forgetting to put things in the foreground of my drawings, so this was good for me too ^^