Rules for the Graphic Section

Your stock is bad, your lighting is bad, the text and the border are horrible.

I like it, good job :)

I love the flow, the lighting fits perfectly, the FG effects are very good, the color scheme is awesome, overall I like it, good job :).

The flow is bad, I suggest to apply image on a new layer and Motion Blur at the angle you want the flow and set it to lighten, lower the opacity if is too strong, the render doesn´t stands too much, duplicate it, put it at the top and set it to multiply, set the opacity to 0-25%

Well first thing, It's always good to get a good quality render. They are always easier to work with and look good. Next is your background. It's a nice background and all, but the colors and designs just don´t go with the render. Always try to use colors that match or compliment the render. The effect in the palm in the 2nd and 3rd versions are good. They give a sense of some action to the signature. Lastly your text could use some working with. Get a good amount of fonts because it's good to have a font that matches the style(techno, curvy, weird, etc.). The white color isn´t so bad because it's easy to see and doesn´t stick out like other light colors would. But you should try to apply a softlight filter on the text, that way it'll be more transparent and it'll have the design of what's under it.