I just downloaded the photoshop 30 day trial and this is my first. It's been a while :/ Note: If I decide to use this it will be resized... My only problem with it is the txt so I'll mess with that. Stock @ URL: Bungie.net : Halo 3 File Details
IMO You need to work on: -Defining your focal -Adding Depth -Adding a Light Source -Making the image signature sized (you currently have it larger then some people's desktop wallpapers! This would be considered more of a Large Piece then a signature) - Working with Gradient Maps and Adjustment Layers to add some color. It's not bad for a first, but keep the points mentioned above in mind for the future if you decide to continue your photoshop career.
meh I whipped it up in approx 5 mins... I would resize it if I'd use it but for now I'll probably leave it be. and no, I cropped it, then burned the outer edges, dodged the spartan and the light around him and added txt But IMO it's not my best, but I'm also pretty rusty(been a year since I've had free control of PS, Graphic design class limits us to black and white with vectors only ATM)