I think those are good exercises -- thanks for posting!
I used to struggle a lot with shyness and being afraid to speak up, along with being incredibly self-conscious about everything I said or did.
I wasn't incredibly social growing up, but it wasn't until late high school/college that I started to realize that I was pretty bad socially. Realizing that I was awkward and uncomfortable to be around made things even worse, and just made me become more and more introverted.
What really helped build my confidence though was not only discovering personal development (John Assaraf, Tony Robbins, Brian Tracy, Jim Rohn, etc.), but joining Toastmasters International.
Working on public speaking and leadership in a safe environment where everyone has similar goals and supports each other was really liberating, and it really helped to build my confidence.
A couple of years of public speaking/personal development gave me the confidence to give independent keynotes at universities and even pursue new business ventures outside of my normal job as an engineer - things I never saw myself doing only a couple years before.
I think the positive thinking/reconditioning does make a difference, but what made the most lasting impact on me was taking action/doing what I was afraid of.
I actually read a great book on self-esteem, called the Six Pillars of Self-Esteem, by Nathaniel Branden (I actually wrote about it here:
https://curtisyungen.wordpress.com/2016/04/25/how-to-improve-your-self-esteem/).
It says one of the cornerstones of self-esteem is self-efficacy. I think by developing our skills (particularly those in communication and leadership) makes a huge difference in how we see ourselves, and how we interact with others.
Anyway, great post on an excellent topic!
-- Curtis