Now I'm going to tell you the steps of how I created this maniacal Batman villain. First I drew it on pencil with a blue pencil and inked it with a nib pen and India ink. Then I scanned it onto my computer.
I opened the file with Photoshop, and started coloring the flats. These are the plain colors that fill each shape. Once I'm finished with that, I start shading the colors in, to give the picture some depth.
The Dodge tool brightens the colors. The Burn tool darkens them. Once I "burned" the edges of the Joker and the other stuff, it looked like it does now.