Originally posted by Luis7uarez
Unnecessary smudging off the face.
Focalise the text more.
Work on light source. The light on the render is coming from the top left of his forehead therefore the light source should correlate this.
Stick with a 1px border or none at all it'll make it look cleaner.
Save your image as a .png it's better quality in my opinion :p
You've got a bit of flow going on, work on the left side of the signature more though.