Light source= in this case just use a 300px white soft brush in top left corner.
Render= Use HQ renders, this looks LQ.
Text= it is good that it is small, but the font doesnt suit.. Add a clipping mask to text.
Blend the render, atm there is no blending at all.
To improve go to deviantart and type in ``sig tutorial`` or go to youtube if u want to learn with a video.