We all have different organizational styles.  Classic planners are generally best-suited to a particular organizational “type,” and they often aren’t very effective for those who don’t think the “right” way for their design.  My sister uses Post-It notes.  My mother uses index cards.  These are perfectly fine, as long as you have a system for maintaining them!  (Both my sister and my mom do.)

If index cards are your style, but you don’t find them very convenient to carry around, consider following Sara’s instructions for an index card holder.  Her holder is designed to go inside a “half-size” binder, but I’m sure it could be adapted to other uses, as well.