I'll add to this list something that I missed (even though it's a major pain in the butt for the DM): Timekeeping. There are consequences for "taking 20" for every 10' square of a room to search. Maybe it's a punishing wandering monster table, but more often for me, it's intelligent dungeon dwellers that make preparations for the terminally loud and raucous adventuring party while they take their time moving from room to room.
One of the interesting aspects of old D&D - and I speak more about Moldvay Basic than AD&D here - is that it has a very nice flow of keeping track of time and the wandering monsters then add time pressure.
(AD&D had those elements, but, alas and alack, failed to explain them. There's no actual explanation of the wandering monster procedure in the AD&D rules!)
Once I combine AD&D and Moldvay, I come to this form of keeping track of time, which I intend to use.
For these examples, I'm assuming that the speed of the party is 6"
* "Exploring" actions take place on the turn scale (1 turn=10 minutes). When you search a room, it takes a turn. When you engage in combat, it takes 1 turn. (Admittedly AD&D has 1 minute rounds compared to the shorter rounds of Basic, but I hope most combats don't go above 10 rounds...)
* Movement rate when mapping is 60 feet per turn.
* Movement rate when not mapping is 60 feet per round - or 600 feet per turn.
* Standard Wandering Monsters will be encountered 1 in 6, once per two turns.
I certainly know that this group hates mapping... and they also have Greg, who managed (when the group lost a map once due to the mapper being teleported away and enslaved by a Knight of Hell) to guide them flawlessly out of the dungeon two weeks after the previous session, despite me using elevators and the like.
Cheers!