Try your hand at the following two Photoshop Tutorials and post the results to your blog.
http://www.psdvault.com/abstracts/create-sci-fi-style-laser-light-effect-in-photoshop/
http://www.psdvault.com/drawing/create-awesome-abstract-nebula-circle-shape-in-photoshop/
Then look down the following list of additional tutorials and chose at least one more to try out:
http://psd.tutsplus.com/articles/web/dark-futuristic-photoshop-effects/