I've revealed before that I used to create custom Mego action figures. It started in 1998 after I completed my vintage Mego collecting and I wanted to add the "essential" characters. I'd say realistically, that would have been Green Lantern, Flash (as true Mego oversights) and Black Canary and Scarlet Witch as "you need a better M/F balance."
The list of essentials grew and grew... I made and re-made them as I got better... JLA... JSA...Teen Titans... X-Men... Avengers... villains... obscure characters... it was really addictive. At first I would pull art from comic books for the custom boxes I made. But then I converted fully to my own art.