In my personal experience as a monk, I was big on mantras. Whether it was a prayer that I repeated hundreds of times, or if it was a positive affirmation. Both prayer and positive affirmations were important for me because they helped me clear my mind. In the Orthodox Church, they do this kind of prayer every day, saying the same prayer hundreds of times. This was to accomplish connecting the mind with the heart. They wanted to pray with the same phrase that even when they were sleeping their minds would pray subconsciously. I have found in my experience that putting in this same practice with positive affirmations has helped my self-esteem and confidence. It's been as easy as saying "I love myself", "I'm a confident person", "I get things done". Say any one of those phrases a hundred times and see how you feel.  https://MonkMindset.com