I saw someone explaining how he had bought an extra copy of the latest D&D books, then he removed the binding, punched holes, and kept them in binders so that he could have just the pages he needed for an evening, say the relevant classes, rules, or monsters. This is especially handy for encounters, where you can have all the monsters for each fight neatly stacked together, and if one type of monster is the main foe for this adventure you can clip that one to your DM screen.
And all this is just amazing. We have re-created the 2nd edition Monstrous Compendium. It’s a generational cycle.