Sometimes, just a small hint is enough to give players image of what's going on and give them the right feel. And perhaps help everyone remember some environmental modifiers too. This is true with the torch & light markers I made years ago, in addition to helping to remember that characters can't see everything out there.
As I mentined in my post showing various terrain tiles/components, I bought Black Scroll Games' castle tiles some time ago. While the tiles look outstanding, putting castle setups with corridors was a bit clumsy. BSG's video suggests using tape, but drawing and cutting tape isn't very handy thing to do in the middle of a game.