I often use index cards to keep track of my plot. I try to write short statements related to the action of the story on cards. Sometimes I spread them on the floor to “see” my plot. Sometimes I tape them to a display board.
In addition to using the cards for plotting purposes, I also use them to keep track of important bits of information, such as my character’s school schedule. These are the cards for the novel Invisible Lines. I have a new set of cards for the book I’m working on now.