Behind My DM Screen
A 3x5 index card with short adventure outline, treasure hoard, and creatures/NPCs (with page references to stats) on one, rumours on another, and a third with bullet points for the night and note taking laid out in front of me. Maps sketched it in little notebooks or drawn on A4 for the players.
Cards with random encounters (basically mini adventures), other plots/adventures, last week's notes, potential wandering monsters, special magic items, and local information held in a small plate holder.
I put them in a small traveler's notebook at the end of the night.
6x12" screen has reference tables and I place tiny foam models I've made on top as an initiative tracker and I lean my books on my chair for reference, monster stats, etc.
As answered on Reddit