I used to be very afraid of getting up in front of people and speaking. I would get sweaty palms and my stomach would be so tied up that I wouldn't be able to eat. I would experience so much tension in my neck and shoulders that I would almost always have a headache by the time I had to speak or shortly thereafter.
Each time I spoke though, I noticed afterwards that it wasn't that bad. This is a trend I've noticed throughout my life. Things I fear are never as bad in reality as I make them out to be in my mind.
So one element of training for fearlessness is to simply push ourselves to do things that we fear so that we have more opportunities to develop the wisdom that the things we fear are always worse in our minds than they are when we actually experience them.