It would be better to make the ball itself wihin a square area so that you end up with a round ball instaid of a oval one. Also i miss some glow in the image fire do glow. The shape itself seemes "flat", almost concave in shape and not sphereic shaped due to smaller cracks and details thowards the center. Havnt tested but a sphereize or inverted pinch filter may cure that.
Otherwise a very simple and nice tutorial for beginners, thx for taking your time to share this as a video.
Keep up the good work,