Lots of articles written about this topic. Emotions make you blind. You deliver “I-have-a-dream” sort of speech and think that you won the heart of your counterpart, then you get frustrated seing that your emotional tirade bounced off the wall, so you start boiling. 🙂
My advice, be yourself! If you shout on your counterpart, apologize and carry on. If you are nervous, pause, explain the nature of your behavior, let your counterpart understand. Don’t be afraid of emotions. Once you cool down and can clearly think, make a recap together so that in your passion you’re not carried away too far.
When you leave the table make sure that all parties have the same version of the event, the result is well noted and follow-up actions planned.
2nd row 5th from the left. Practice (a lot)