Though I have met surprisingly few dedicated game masters with more experience than I, I have sought out and read a lot of good advice over the years. This has, I believe, served to improve my game considerably, and helped me develop a complex and unique approach to DMing, tailored to my strengths and allowing me to constantly focus on eliminating my weaknesses.
I am a "the game is about the players, not the DM" propronent. One approach I have taken to facilitate this philosophy is to increase my awareness of the individual needs of the players.... It has become obvious to me that, whereas we are generally all involved in the game for similar reasons, the specifics tend to vary dynamically from gamer to gamer. Most of my players are "purisits", dedicated to the individual development of the character based on the PC's personal experiences and philosophies. Above and beyond that, however, I have an "artist", one who creates and develops the character for the sheer joy of artistic expression, an "escapist", who sinks herself deep into the psyche of the character to get away from "real life," an "architect", whose pride is in the unsullied construction and development of the individual, a "strategist", who attempts to approach his character's experiences with a directed goal, trying to construct a more effective character, and so on.
The trick is to provide a means by which each of the players individual needs is provided an appropriate challenge, creating expressive levels of satisfaction among the gamers as the campaign takes shape. Ultimately, my goal as a DM is to offer the players enough access to the inner workings of their characters to allow them to play the game on their own terms... while challenging them in ways that appeal to their individual needs. Once a player is firmly seated behind the eyes of his/her character, supension of disbelief is a breeze.
I realize that this isn't advice that I've received, but it's one of the many presentation philosophies I've developed for which I often receive funny looks from other game masters. In terms of general advice, I would be very curious to see how such concepts jive with other gamers' ideas.
And, of course, if my players have a good time, I have a good time. I tend to examine every idea I intend to implement in my game to ascertain that I am working toward that goal... not some private institution.
Best advice I've ever personally received...? Suspension of disbelief is the crux of a good game. Learn it. Live it. Love it.