Hi, kimey.
Again, thank you for this excellent and quite fun tutorial. I've tried my hand at it and, as you said in your post, it isn't an "exact science". Nonetheless, I found your tutorial very useful, educational and fun to do.
I've attached my first nebula called the "Horsehead Nebula". I found a cloud picture that when put on its side, resembles a horse head and just had to use it.
Endjoy.
Regards,
Vandy