I found reading about Zen and other Eastern ways helped me become more comfortable in spontaneity, which increased my confidence a lot. Quick-on-feet helps so much.
"The qualities inherent in expressions of Zen include spontaneity, simplicity, directness, naturalness, austere sublimity, subtle profundity, freedom from attachment, and tranquillity. Exposure to these qualities can resonate at the profoundest level and provoke an unbearable dissatisfaction at their apparent absence from ordinary everyday life. Yet Zen is fundamentally about ordinary everyday life." - Zen: Definition from Answers.com