Hey, it's an alright banner.
I gotta say, the bordering of the banner is unique.
I want to suggest, though, the brush strokes/usage behind the border of the banner was cut off. It leaves a weird look. I would probably go back and give a fuzzy blur to it. Maybe use a soft brush, enlarge it or use a large brush, and erase the edges of the cut off brush use.
The text - too pixely for the edges. Why does it have such a hard edge to the outlining of the text? It doesn't look good with the banner at all. =[
Use another font, and try to make it have a flow to the banner. If you don't like that suggestion, I would probably just add some glow to it. Also, get rid of the gradient of the text. It looks better with a solid white color, imo.
It's a pretty simple banner - great for a beginners banner. I'd probably experiment more with your render, colors, text, lighting, and possibly, some effects for the banner. With some effects, you can create a more interesting banner. You've probably seen c4ds being used in banners, which can help create a more interesting banner. It could also help create depth and flow, which becomes more important to making your banner a little more realistic.
I'm going to suggest play around with your render and maybe practice smudging? It's a really cool tool that can help you a lot to create an effect with your render.
I think that's all I have for ya.