Confidence can't be taught - but it can be built
I was having a new set of headshots done (incorporating my glasses as due to suspected sjogren's syndrome I've bid contacts a long-term farewell) and worked with the same (superb) photographer, Nick Freeman as last year. He had taken notes from our last shoot and was putting them into action when he stopped and said "I just need to move the camera back - you're coming across more dominant than you were last year."
Last year was the first year for a long time that I had professional headshots done, and last year was also when I was just coming into my own in terms of being a keynote speaker. This year - I'd got used to it - and I hadn't even realised.
One of the things my students always ask me in our public speaking sessions is "How can I be more confident" - many rarely like the answer - PRACTICE (and with speaking - OUT LOUD!) Confidence is not something you can "put on". Of course I can teach you how to stand, how to make the most of your posture, how to do the "power pose" to feel more grounded before taking the stage. I can also teach you to take a couple of deep breaths and as you do so, rehearse that first line so that you slip into your stride seemingly effortlessly, but confidence will only come with practice, and ideally experience.
This is why I am such a strong advocate of experiential learning.
Think of a trainer in the same way as any health professional - without seeing what is going on, you cannot diagnose nor treat effectively, and whilst delegates are performing their skills (so you can watch) - this is also an opportunity for them to practice...and then reflect with you...and practice again! The more times this is done, the more confident they become, at least in the area of effort.
My public speaking sessions will take you through persuasion, questionning, posture and stance, projection, breathing, annunciation - along with "first lines" and "summaries" - but the biggest gain you will make is by standing up and having a go - every time. This is the same with any skill. Even if you are not blessed with a natural talent, the more you do it (and sometimes you may need the guidance of a tutor), the better you will be because you will become accustomed to it...simply, your confidence will grow.
It was such a thrill to recieve one of my lovliest emails yet from a public speaking student - who has always had the ability and intellect, and just required a tiny bit of refining which read "Just wanted to say thank you again for the public speaking classes. I had to give a 15 minute presentation today to a senior manager in IBM, and his feedback was "So, I see you do these things often". "Often" in this case was once a week - with someone who was always willing to try.
Too often - and I am guilty of this too - do people overthink or analyse something rather than trying it. In some cases, the brain does need to understand before it can act, but in many many more, this is a (very good) stalling technique.
As a trainer - create the right (safe) environment and encourage participation.
As the "performer" - have a go - your next attempt will only improve.