Well since we have so many threads on adventure seeds and the like, I started this one on favourite narrator tools, such as music, cutscenes, etc. I know there are already other threads that cover that but only on each own and not together. I intended this topic to be a source for other narrators to use to improve their own techniques, thus do not spare with explanations and examples.
So come my favourite tools:
Music: First of all I usually try to find a theme song which makes the players get into mood and tone of the campaign. For my current post DW TNG campaign I use the title The Jihad from Children of Dune, you may know it from the trailer for Master and Commander. It is epical and grand as well has a noble sound. Along with the trumpets it still sounds trekkish, so I chose this more or less as the theme for our ship, Galaxy-Class USS Allegiance. I do not only play it when beginning a session but also within the story if the ship or crew is performing a very tense task. Luckily there are different versions of the title on the CD, even a sad and less dramatic one which I intend to use if one of the characters dies ( which will happen in on of the next episode, or at least the players think it happened ).
Cutscenes: I experimented long with prewritten text read out to the players. It is a very useful tool to give information to them and along with it set an atmopshere. However I made the experience that too long passages actually hinder the players more than it does good, so I keep them pretty short. Most often I describe places or persons that way, which is also helpful when portraying/ acting them later on as Narrator.
Another opportunity to use such scenes are flashbacks, which help develope a character more. It can be a dream, a recall when seeing a photo, the actual appearance of a person or other stimuli, which cause the recall. Thus far however I used it rarely as my players prefer to develop their backgrounds themselves ( which I feel they do too less, however ).
Scenery: I do not mean within the story, but in reality. We once experimented actually using Starfleet Props, even uniform during play - but in the end we actually felt it was silly and distracted more than it was useful. However during one very long and great MERP ( the old Lord of the Rings RPG ) session, I had prepared the room with candles, since it was evening, and the playing table with an old cover, along with several props on it. there was a sword, a horn and wood-cups to drink. Additionally I had managed to get my hands on a hobbit-cook-book and prepared some of it ( actually it was my mother, I did not want to kill my friends ). In the end it turned out great and the players liked it.
Imagery: Usually I try to describe with words or sketches to makes sure that the players see what I intend them to. However sometimes it does not suffice, especially if I want to create a not so well-known atmosphere. Then I use images found in the web, mostly real art, to present the scenery. Not rarely its is also the other way around, I see a picture and try to incorporate the feeling, scenery of it. One source I use is renderosity or if I have the scenery first and try to depict it, I do the picture myself. Mostly I do it with characters, how you can see at my homepage.
For my current Mage: The Ascension campaign I actually created a short movie, trailerlike, to get people into it.
So that is pretty much it, so what techniques do you have?