The greatest gift in the world [listening]

Listen more, talk less. If talk to much, you may say the wrong things and prevent others from talking. This is a huge mistake since good listeners pick up useful information. As the quote say "the less said, the more heard." as my lecture say "listen as twice as you speak"
When you get angry don't loose your temper. You wont win by losing control, and your could make bad judgements.
Direct confrontations do come up in negotiations. Often it just takes creative thinking and and flexibility to move towards agreement "Let's think this through again and meet tomorrow." may be all that's needed. But sometimes frustrations arise, tempers overheat and there is a real threat of total breakdown. So reintroduce a sense of progress. Is there a Minor issue you haven't discussed? By demonstrating your ability to agree on lesser point, you might approach the major one with fresh eyes.
Keep your commitments once you've made a deal, live to it's terms. Don't give your word lightly. but keep it once you do.
If you have shown intergrity in all your dealings, people will know you about it. If you change you principles as often as your socks, you will also be known for this. But if people have learn to trust you, there isn't anything can't accomplish.