Ok, I'll try to point out some things you maybe should pay attention next time you start working on something new. *_*
1.
Text: If you put big text in your tag you instantly make two focal points. Focal point is, as you know, the thing you want to be noticed first by the eye of a viewer. In most cases that's render. When you put big text next to a render then the eye of a viewer may be confused on what to focus on the tag.
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2.
The rule of the third: This is like the most basic principle of photographic composition. It's not obligatory to use it but with it your tag will look more balanced. Just break an image into thirds (both horizontally and vertically) so that you have 9 parts like this:
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Now, you just simply need to place the focal where lines cross each other. Also, these lines can also help you with placing other things in your tag. Like C4D, lighting etc.
3.
Background: Basically, when you are making a tag you should keep in mind that you are placing a render that you chose into completely new world. But if you are doing that, that doesn't mean that you can take any random BG and put it together with render, especially, when you are making tags which are solely focused on BG and render itself. They must kind of function as one thing.
4.
C4D: Using too much C4Ds is never good but you can always try using some of them just to make tag more interesting. Also, that would help you with BG too and that could add maybe better flow to tag. Not to mention that you could experiment so many things with them. So don't afraid of trying something new. Very good GFXers do it like this:
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Hope this will help you! *_*