The render is blended decently well but it looks too busy. The background doesn't flow and the lighting is odd.
Well I see your a smart artist I like your little comment about no text because you can't do it. That's a good thing because if you can't fit the right text it'll just ruin the signature to begin with, but make sure you always try 2 make a text work so you atleast get practice on it, otherwise your artwork will get better, but your text placement wont and you'll still struggle with it later. Now onto some C&C .... Background: - It's to dark and bland, there's nothing really there for structure within your signature. No matter what you do with you background make sure when you create it you put the same amount of effect into it as any other part of you signature, even if you plan on just blurring it out because it'll make it leave a better effect and add depth to the signature. Effects: - The render seems to be in some sort of motion, because obviously he's a football player and he's running so keep that in mind when your adding you effects, you should want 2 emphsize the motion of the render with your effects so have them trail behind him. Render: - He's popping out as the center of attention TOO much, yes you should have him be the most noticable, but whats the point of the rest of the signature if you can't really see anything but him with a little bit of effect on him and a blurry monotone color background. Advice: - Start with looking around at other signatures, and maybe asking for the PSD if the owner's willing to let you look at it for learning rights so you can get some ideas on effects to use on your own tags. This way your learning and seeing a good way to introduce new effects, better focals, lighting, depth, contrast and everything else you pretty much will learn in your own time, but this way you'll speed the process up a little more. - Your not a bad designer you show great potential, just work on a few things. Don't take my comments out of context though, I'm not saying change your style I'm just saying learn a few things to toss into a signature. I only posted to help so I hope I did