I'm liking this. You've improved a lot. And, if you pay a bit attention to what I say, you can indeed become a very good graphics maker.
Reduce the dimension of sigs you make. 450 x 150 is perfect IMO.
The right side of the sig looks jaw-dropping. It's fantastic. But the left hand side looks the reverse of it. Those arrow brushes don't actually make sense. You could remove those and brighten up the left side.
The Warning brush is pointless. It's terribly placed. The text is nice, but reduce its size. Move it closer to the render. Then add few soft brushes over the text in a new layer and set that layer to overlay.
For blending, soft brushes can come in handy. Also, put a photofilter when your sig is done.
Cheers.

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