Writing a Children’s Book that Sells

4) Provide a nemesis that makes sense. The antagonist in your story should appear to be everything that your main character is not. Then go back in and give him or her some good qualities as well. People are not good or evil. Your characters should have the same character traits, as the rest of humanity. lemony snicket Ex. A Thief with a Conscience or who hates everyone except his little sister, who he has taken care of since their mom died. Give all your characters depth. 5) Provide obstacles for your main characters. Both your hero and antagonist need to have a few bumps in the road. Life isn’t smooth. Let them both screw up and figure their way out of their messes. Daniel Handler