I would recommend everyone involved in teaching mathematics to read the book “How to teach mathematics” by Steven G. Krantz. It contains lots of practical advice about how to improve your teaching.
After reading the book by Krantz, I started to pay more attention to “small details” which may have a great psychological effect in teaching, for example, a very clean blackboard before starting each lecture.
A review of the book (2nd edition, 1999) can be found here:
One can find the book in many online bookshops (and can also download the book from the internet if one can’t afford to spend 20 dollars on it)