Mystie at Simplified Organization uses a 3×5 card for her daily to-do list.
Jessica from Life as Mom uses a 3 inch square post it note.
as much as i love index cards, for me the sweet spot is the 2.5 inch post it. any bigger and the note just doesn’t fit my day. most days i can plan on space for one extra in my day. one outing or one chore or one hot spot. just one, not all three. the tiny size helps keep my productivity expectations in line.
doing a morning review helps me see where i can best focus my (limited!) energy and attention. and an evening review helps me to really see and appreciate all that i got done. even on the most unproductive days!