I liked my sticky flag holder in my junior Circa so much that I adapted it to my letter-size work notebook too.
I used a letter-size Levenger top-tab divider and a gluestick to keep the post-it flags firmly attached.
I love how the flags are exactly the size of the appointments section of my work planner page.
Which post-it flags you ask? These!
I just love arranging them in ROYGBV order.