first fill the layer with blue color, add some lighter blue on the horizon line, and some darker blue above it. the sky is getting darker the farther it is from the horizon line
second add some silhouette of grass, tree, home, and some random people too, this part is up to you. feel free to add any kind of silhouette, just make sure they look nice. copy this silhouette layer and flip it vertically.
third add some fire with a light yellow color
fourth add some smoke too, use the airbrush and the water brush, and then add some fire reflection below the burning fire
fifth add some stars with pen tool, and then shrink it, repeat this step on another layer until you are satisfied with the stars. Glow the stars using airbrush on luminosity layer on 30% opacity/. don't forget to add the moon too. a
sixth add some water waves on that lake, use the brush and then the water brush, strokes horizontally, with short and curvy brush stroke to make the waves
7th add some glow on the fire and the reflection using overlay and luminosity layers
8th fill the new overlay layer with blue or purple to balance all the colors, then reduce the opacity.
9th-10 fine tune the saturation, contrast, brightness, shadow, etc on another software
i used google picasa 3 for this
hope this help