I think one of the best ways a DM can learn how to become better is to actually play the game as a player with some frequency. It helps to open up the lines of empathy to the player's situation as well as gives the DM a bit of a vacation... it is so much more relaxing to only have to be concerned about a single character rather than the whole milieu! One of the things I have learned as a player that I believe helps the game to move along is to think out loud. Let me try to explain.
The game revolves around the DM and the players sharing an imaginary landscape between them, wherein all the action takes place. The majority of the burden of description is with the DM, but the players are also responsible for a great deal of setting creation of their own. The key point is the fact that the world only exists in everybody's imagination and the only way a functional game can happen is if everybody is on the same page as to what is happening and what possibly could happen. Even a slight breakdown in that consensus reality can cause than whole game to grind to a screeching halt.
I've been a player in a game where the DM set up a complex trick room that required a lot of thought and experimentation. It was fun for a while until hours started to pass with no success on the horizon. (The situation was such that the characters retreating was not an option.) Things ended up breaking down into player hopelessness and DM frustration. Later, when everybody talked about what had happened and the DM explained the simplicity of the trigger, the players were convinced that they had already done that very thing trying to work out the trick room and had become dejected when nothing else would work either. The consensus reality between the DM and the players had broken down and left everybody feeling shitty about it. And it was on a very minor detail.
I am convinced that such a situation may have been avoided if the players had engaged in the simple activity of thinking out loud. If, from time to time, they reassessed the different ways they had attempted to trigger the trick room... out loud so that the DM could hear their line of reasoning... then the DM could decide if the players were on the same page as to what has actually happened in the situation, and amend the details if necessary. ("Oh wait... you guys think you dropped a gold coin into the left slot? I thought you said right slot... ") It is a simple way to occasionally reaffirm the consensus reality between the DM and the players.
I find myself doing this a lot when I am a player, because I have a tendency to hatch some pretty crazy plans in my head, plans that may not actually have a basis in the reality the DM is weaving. So, thinking out loud is also a way for the players to "test the waters" of some outlandish ideas. It gives the DM an opportunity to see into the heads of the players to a small degree and, if necessary, gives him a little advance warning about some wild-ass caper the players are hatching. If this gives the DM enough heads up to keep the game from getting derailed by a surprise course of action that he didn't plan on, then so much the better!
(Now, if you are playing in a game that you don't want the DM to know what you are planning to do, because you are worried that the DM will make sure your plan doesn't work if he gets advanced warning, then I am sorry for you.)