"The most powerful tool in coaching is the question - the Greek philosopher Socrates is regarded by some to have been the first coach. Among other things, he used deversified questions in his talks with his students. Here is how he did it.
My teacher uses a Noise Meter similar to this one. The Noise Meter is a cool way to remind students the correct noise level that they should be using! You just use the paper clip and move it to the appropriate noise level the students should be using.