The One Simple Thing That Can Make You Much More Impressive tells how a university professor got his classes to like him more. They rate him as more knowledgeable, tolerant, accessible and organised. This likeability increased.
They said they learnt more from him. All he did was show his enthusiasm by smiling and gesturing more than usual.
Worth a try!
Goes nicely with this quote – try concentrating on being enthusiastic and show those gestures.