Enter after a person has made his point

It is vital for you to understand that interjections need to be made at the right moment. For example, someone has just started with his points and you try to cut him short. Majority of the times, you would be hard-pressed to leave an impact and it is rare that the other person would give you a chance to cut him short before he completes his points. On the other hand, is you allow the other person to make some of his points, and then enter the discussion by interrupting him, there are greater chances for your success.