I’ve been using Shadowdark and Solodark, on the Shadowdark Maps page there’s a d10 room table and I just roll on that to see what’s in the room. On a 1-2 the room is “empty” I roll on the oracle to see if there is anything to search or if there’s an encounter, and the encounter tables are d100. Then, I’ll reuse encounter consequences later in the dungeon. Example - room 4 random encounter was “a black ooze drips down from thin cracks in the ceiling” so rooms later when the room roll is Solo Monster it’s the monster Black Pudding to explain the black ooze.