You have some pretty nice work here! for a beginner!

For background:
- Choose an image that suits the render (unless your using a stock)
- Similarly, if you make a background use colours that are similar to the render
- Add space, fire, and other stocks (put them on 'Screen' so they blend)
- Or make the render HUGE then use the smudge tool to blend it all up!

For the Render:
- Look at smudging the render, make a few layers, mess about with the settings
- Smudge edges of the render (this is a useful effect)

Other effects:
- C4D, google em to see what they look like, these help add colour and depth to a sig!
- Fractuals (again google em)

Make sure the colours suit (and dont CLASHHH, it doesnt look pretty lol)
Also, very important this, make the tag have some flow

Hope this helps! Look forward to see (and cnc-ing) more work dude