anyways, here are some lessons I've learned from running my last few sessions
1. Randomness on the DMing/encounter generation side of the screen does not necessarily equate to randomness on the player/experience side of the screen. Rather, the players can be given a sense of disorder or mystery from events which are actually carefully planned on the DM side. But if the DM expects off-the-cuff randomness to perform well and hopes to surprise himself, he is likely to be disappointed, and what the players experience will probably be meaningless and boring.
2. If you want a monster to stick around and cause trouble for a while, don't make it easy for the PCs to push it off a cliff or into a pool of lava or something. At least not until that is exactly what they are supposed to do.
3. Dungeons are like fun-houses. The aptness of Alexis-senpai's comparison is more apparent to me now. Except I would say it's more like an amusement park haunted-house ride. \
Things need to be obvious. The monsters are supposed to pop out on their creaky hydraulics. If there's a mystery or a secret, it needs to be apparent that there is a problem to be solved. It's ok to hand-hold in dungeons.
Yeah, I am usually for lots of freedom and player-driven action. But dungeons really aren't the place for that. Open ended adventure requires an open environment. Once we are in a dungeon the game is not about getting into character or storytelling. It is about killing stuff and getting treasure until the course is cleared.
4.That said, whether an area is visually mapped or merely described to players has a huge effect on how they are prompted to explore and interact with the environment.
I had a certain area mapped very neatly, but lost it before game. I felt this loss very keenly as I had to describe verbally what I had expected to present visually.
A map encourages players to be more proactive in their exploration. What they already see is clearly marked and the "blank" areas of the map show where there is more exploration to be done.
But when players are dependent on a description farted out of my hazy and disorganized imagination, they really lack prompting. If something is not specifically mentioned in plain language, it may as well not exist. On the other hand, something mentioned as mere window-dressing may utterly fascinate or boggle the players. The tale of the Gazebo comes to mind.
Does it see us?
This distinction between visual representation and descriptive representation may seem obvious. But I am still learning it. In the future, I will make a conscious decision about how I intend to present an environment. This distinction also pretty much dictates what sort of preparation will be necessary.
5. Mixing monsters is cool. Encounters with multiple distinct monster types are a good way to make a combat more interesting. Having more than two factions involved simultaneously in one encounter can be very unpredictable for players. Especially when one faction is an unknown quantity. It gives players the opportunity to make quick decisions and feel particularly clever when things work out well for them.