Hey Bob,
Did you see the last dungeon we made?
Here's the thread.So I'd suggest doing the same process again, as it worked pretty well:
1. Find a keyed map.
2. Someone takes the next room on the map, rolls to see what's in it, and posts the description. Feel free to put in references to previously described rooms, or hints to as-yet undescribed rooms. Repeat until all rooms are described.
3. Finishing touches, a name for the dungeon, wandering monsters, rumours. (This bit didn't work out so well last time, as interest petered out once the dungeon had been stocked. But the stocking's the main thing anyway.)
For the room contents rolling rolling step I'm not sure what others were doing, but I was just rolling to determine the general content of the room (empty / monster / trap / special), then making something up from that. Others may possibly have been rolling on random monster charts as well, I don't know.
Personally for my own use in my campaign I'd be up for doing another low level (1-2) adventure, but I'm open to higher levels if others are keen. I'm open to any suggestions of maps to use, or whether it should be a dungeon or something else (town / wilderness locale). Any suggestions?