Looking good, I would like to have the psd someday and work on it with you, so you could learn or get some live feedback from me, if that would help. Anyway, you have most piece in it. A background, a render, some effects and a text. What I would add tho, to be more conventional, is a basic lighting. Since the render is looking at the left, the flow is going to the left so I would put a basic soft brush on the top right of his head and work around it. The picture seems low quality too so I could help you find better pictures (by better, I mean higher resolution). But good looking sig.