There are few, if any, parts of DMing philosophy that are Natural Laws. Even things which seem like requirements for any game (e.g. Player choices impact the storyline, Player Characters are the drivers of the story) can be violated depending on system and the sort of game that the Players want to play. So, do with these responses as you will, but don't expect to find any more truth in them than any other random collection of Dudes On The Internet could provide.

Responses
Spoiler
Show
Quote Originally Posted by Trekkin View Post
1. In-character knowledge trumping player knowledge. If a character is about to do or not do something significantly out of the norm for someone in that setting, do you remind them of where they are before they do it or let them do it without comment? As a toy example, when do you enlighten a player who doesn't know that a gazebo isn't a monster, so attacking it is weird?
I always remind Players when I notice they are acting on assumptions that are false from an in-game perspective. In part this is because I run primarily homebrew worlds and I have long since given up on Players reading up on every world I create

Mostly, however, I find that Players don't like having their assumptions shown false in this fashion. To them, it seems very much like hiding the ball -- they should have known what they were doing was stupid as characters, but the Players weren't informed what their characters should have known.

Of course, it is not always easy to tell when a Player is acting off of incorrect assumptions, so I have a habit of asking "why are you doing that?" whenever I notice a Player acting "erratically" from my perspective. It still doesn't catch every time, but it helps a lot.

Quote Originally Posted by Trekkin View Post
2. Adventure leads. If your players are stumped as to what course of action to next take to fulfill their goals, do you try to make the course of action you have planned out any more apparent or let them discover it as it stands?
I never write adventures where this happens. In part this is from practice -- it is easy to write yourself into Bottleneck Adventures, but once you have a few of those under your belt, it is easier still to avoid them. I also am more than willing to use Illusionism to keep the ball rolling if the Players go off on a completely random path and even simple interrogation of Players to see if they've actually forgotten an important clue. I don't use these techniques much anymore, but I always have them in the toolbox to use rather than let the game stall out and not be fun.

Quote Originally Posted by Trekkin View Post
3. Off-session availability. How much of the business of character advancement and things of that sort do you request your players do outside a weekly session to save time? How available are you to answer questions they have regarding the campaign, etc. during this time?
I require my Players to do as little as possible between sessions, and always do my best to answer questions between sessions. Gaming shouldn't be a burden on anyone aside from the DM, and I also find games run smoother when the action takes place in public and under the unblinking eye of the DM

Quote Originally Posted by Trekkin View Post
4. "Ingenious" plans. If the players come up with something totally out of left field and borderline ridiculous (albeit physically possible), do you make it reasonably difficult to try or disallow it?
Depends entirely on the feel of the game and the situation. "Million to One" shots are usually disallowed by DM interrogation (i.e. pointing out fatal flaws in plans) but if the party is really excited about a risky plan I tend to let it play out. Notably, these sorts of plans seldom are Silver Bullets and are rarely preferable to more reasonable plans; I mostly allow them for when the party has placed itself in a bind and needs some way to get out of it and continue the adventure.

Quote Originally Posted by Trekkin View Post
5. Silliness of the setting. Basically, Deadlands is a fairly serious setting, but it's got the odd tenet or monster that's just weird as anything. People who know Devil's Tower 3 will know the one we're currently facing, but in general, do you try to maintain a consistent tone or let things be as unusual as the module demands?
I don't use modules. Every campaign I run is designed with a consistent tone in mind (excepting Breather Episodes, on occasion) and I do my damnedest to stick to those expectations. The more you violate the tone of a campaign, the harder it is to enmesh the Players in it.