I watched a few psychology videos on YouTube, which helped me understand some underlying issues I didn't really acknowledge before, such as a fear of failure and what to do when you lose your confidence. (cheesy but it worked).

I also actively worked on meeting anyone's eyes and smiling back/acknowledging them, that's at work and out and about.

Concentrate on the soles of your feet, really feel them carrying your weigh and what you can feel. This helps you feel 'grounded', literally.

This is about feeling out of control. Imagine that that 'pressure' you're feeling is going into your body then running out of your feet and into the ground. The more pressure you feel, the fast it drains out. This also relates to reassuring your sense of being grounded above.

When you're in a bar or giving a talk, you feel out of your comfort zone. Imagine that a sphere surrounds you and that people can't help but look at it. Repeat that in your head when you're in one of those situations.

Self doubt and all those feelings that tell you you can't do something are poison. Begin by thinking back to the worst moment of your life, where you REALLY felt these feelings. Remember how it felt, the sting of it, the negativity you felt. Now imagine that your pushing those feelings into a tiny ball, it's getting smaller and smaller and smaller until it's a tiny ball. Then it's gone.

Now think about your happiest moment when you felt really great about yourself. Remember the warmth you felt, the happiest washing over you. Now imagine your blowing that up, bigger and bigger and bigger. Feel the warm grow and grow and grow.

Practice these steps every day until you've really mastered them. Now in a social or public speaking situation I unconscientious 'crush' any feelings of doubt and feel so much more confident. It's what stage actors and tv people do a lot. Public speaking is about controlling your own emotional state