To be honest, it's probably one of the most annoying sigs I have ever seen. Not because its bad or anything, its just that the intesity and mixture of colors gives me a headache. The one you are using is alot better.
The render doesn't match the background at all. Try using colors from the render to make it blend in to the sig a bit more.
Read some tutorials on brushing, smudging and effects. Then just keep practising and you'll be better in no time.
^click to see some of my signatures^ Please leave a comment ^^