Planning my Artworks

Figuring out what I should create, what story/part of story I want to portray, composition, themes etc

I settled on the three final artworks being loosely set like playing cards (joker being on normal playing cards link). 
First Artwork:

• How Harley and The Joker met
• When they start to fall in love
• The Joker's mouth is bordering the scene

Second Artwork:

• On top half The Joker is electric shocking Harley
• Bottom half Harley and The Joker are dancing (reference to Alex Ross' painting, was also in the movie)
• Dark shadows border the picture

Third Artwork:

• When the Joker and Harley fall in love
• Top half is the Joker, bottom half is Harley in their insane (but happy) state of minds -they "complete" each other

Rough Sketches of Composition: