Really low quality. Make sure to always save as .png for highest quality.
Very bright.
Terrible text. I see you tried something new with the clipping mask over the text, but it really does not work on this sig. It doesn't blend at all.
Your lighting is off. If your light source is at the top, all of the lighting in the sig should be based off that idea.
Lacks depth.
Background is boring and empty.
Does the render have a stroke on it? Strokes on renders is almost always a "no-no."
You are improving. Keep practicing

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