Currently I’m reading a book about starting to write for kids using stories in the Public Domain to launch your own works from.
One of the novels that I had great success with in NaNoWriMo was a young adult one. This was only a first draft and several revisions away from really being good, but I may have a modicum of success in that field.
That same method can be used for work for adults too. Snow White
led to the classic animated tale from Disney, but it was also the template for two recent films: Snow White and the Huntsman and the Julia Roberts dud Mirror, Mirror
as well as one of the storylines on the TV show Once Upon a Time. Grimm’s’ Fairy Tales led to the TV show Grimm.
I could easily use such PD to create adult tales!