I used this picture as reference for it. I printed it out and measured everything out completely, all the distances between lines, circles, letters and so on, wrote it all down. Then I figured out how big I need my Halo of the Sun and then adjusted the measurements for how they would be on a big version, the one that ended up on the door. Used a straight ruler and pencil, drew it in pencil first, then painted red over it.
If you want the description more detailed (because I know I SUCK at shortly describing things) let me know, and I will send you a note in the next few days with a detailed description