A great resource including printable template:

One of the oldest tools in the arsenal of writers is the modest and unassuming index card. It's used for jotting notes, sharing phone numbers, creating bibliographies, capturing ideas, making lists, and --heck-- even making indices. (Who would have thought?) But one of its primary uses, especially for people structuring stories, is in creating a plot outline. A pen, a table top, and a small stack of cards are all that's needed to turn a mish-mash of incongruent or half-baked ideas into a plot that's tight, logical and well-developed.

Have you ever come up with a concept for a story, video or presentation, but didn't know how to begin?

Read full article at D*I*Y Planner.