All my life, I have known that encouragement works better than belittlement.
Looking like you are irritated, annoyed, frustrated makes the other person feel bad. They internalize that feeling and then they fail to perform.
Instead, smile, be open minded, say please and thank you, show them that you think they can do it.
It may seem silly and it may go beyond what is needed to work – such as medals for participation and empty platitudes of “great job” – instead basic, simple encouragement works so much better. Plus, it is so much nicer to say “I knew you could do it” than having to say “I am sorry that it didn’t work out.”
~ Dawn aka Hat Girl