First off...In all your sigs you need to use better renders...You used low quality renders that make the
whole sig look low quality. Next, you need to be more creative with your backgrounds. Try many different types of brushes until you find something that looks nice, as well as using different blending options and filters to spice them up. Also, be sure to blend the render well, especially with big sigs like those. Experiment different ways to blend a render. 0When using filters on renders make sure it contributes to the whole sig and not just the render. A filtered render not well used looks out of place and unattractive. Finally, as far as text goes, its your choice.

You have a good sense of render placing which is good. Make sure to take constructive critisism and keep practicing...You will only get better.

Nice work.