Write a one-sentence summary for each chapter of your novel on separate index cards. For example, your first index card may read "Chapter 1: Louise overhears her boss discussing plans to fire her from the law firm." Joyce Lavene and Jim Lavene, in "The Everything Guide to Writing a Novel," explain that outlining the overall plot for your novel on index cards makes it easy to move chapters around if you need to change the order of the action.
Use additional cards to develop details for each chapter. Barbara Shoup and Margaret-Love Denman, in "Novel Ideas," recommend using a question-and-answer method to develop your ideas. They suggest seeking to answer questions such as "What's introduced" and "How many scenes are in the chapter?" for each chapter of your novel. Jot the answers to these questions down on index cards for each chapter, such as "Chapter 1 Characters: Louise, her boss and an unidentified coworker."
Develop the action of each chapter by sketching individual scenes on index cards. Shoup and Denman explain that you should use one card for each scene that occurs in a chapter. They suggest answering "...the who/what/when/where/why questions" for each scene and then "...jotting down observations about character, time, and place as you go." Once you have summarized each individual scene on an index card, then you can experiment with organizing the scenes in different ways to discover the best order for the chapter.
Add additional index cards to aid in the development of other aspects of your novel. Catherine Lanigan, in "Writing the Great American Romance Novel," explains that you can use index cards to develop characters, describe settings, explore subplots and outline research for your novel. She recommends giving these topic-specific index cards headings, such as "Characters," "Weaponry," "Settings" or "Clothing," so that you can quickly identify and access the information on the card throughout the writing process.