Humour
I love humour myself and have always appreciated teachers who use humour, whether by telling jokes or just through a general humorous demeanour and lightness of being. It seems to me that humour relieves tension, gives energy, provides variety and puts things in context. It is an important part of establishing warmth and rapport, and is something that all can take part in (as long as it is appropriate to the learners concerned).
In a review of the literature on humour in education, Krause (n.d.) concludes that the advantages of using humour include: gaining attention and interest; stimulating memory and learning capacities; creating a positive, relaxed environment and relationships; reducing the authoritarian position of the instructor; and positively influencing the learners’ perceptions of their own competencies.
In my own teaching, I often use humorous cartoons, video clips or amusing anecdotes. It is not always easy to find something that exactly fits the topic of learning, this is not necessarily a problem as it is the feeling of amusement and the act of laughing that provides the benefit.