All these silly comments, The first has a little CnC but the rest is so silly.
The sig is very small try using a bigger canvas a nice size i found to be is 400x150 but there are opinions. It's too monochrome which doesn't look good and the effects are very minimal, Don't center your render as it makes it look worse. Try not to make all the colours the same and but do still have a colour scheme, there are many tutorials on what colours go well and contrasting and all different things.
A few tuts with nice outcomes could help, It may sound stupid that I say look at tuts in every one of my posts but they are such a key ingredient to getting better.
Yeah, I agree can you link me to some tuts, because I always find shitty ones and I asked favo and he gave me an amazing link lol