Paint rooms and corridors on a square grid, or let the generator lay out a dungeon from a seed, then place the doors, the secret doors and the traps. Every numbered note becomes a line of the key under the map, so the page is the whole adventure.
Keep the numbers, the traps and the secret doors on layers marked for the game master and print the players a map without them, as the party maps it. Three looks: the old-school blue, a crosshatched ink drawing and a blueprint. A4 or A3 at 300 DPI; for a fight at one inch to five feet, use the Battle map.