How can I improve my conversational skills?

Answer: State your opinions gently rather than dogmatically.

In How to Have a Beautiful Mind, de Bono advises us to replace “sweeping generalizations with less absolute statements” and gives this example:

Sweeping generalization: All sex offenders should be castrated.

Softened version: There may be a place for investigating hormonal treatment of some sex offenders. (p 63)