They aren't too hard! I found some tutorials on DA. Pretty much you take a texture, like maybe a google maps terrain one like I used, transform it's perspective. Crop it and play with glows and colors and what not. The stars are a stock cause I can't make easy ones since my Photoshop is old (7) so I don't have the necessary filters/brushes to make my own. I've been looking for some brushes that work with my version so I might try stars again. The sun/star is just a simple lens flare!

Pretty much just do the photoshoppyness until you feel it looks good