I had a very bad argument with my friendship group around a year ago and I didn't handle it well, it affected me in a very bad way for months. If I could go back and change anything, I would have told myself that it was my fault and that the people I hurt, they were my responsibility. Nonetheless, I am actually back in the friendship now purely because I learnt from my mistakes. I don't gossip, I appreciate my friends and I realized my flaws as a friend and how I could improve.
Using an example like mine, if you've said something nasty about one of your friends and they decide that they didn't like what you said. From my own experience, I say step back, take a breath and assess the situation. You might say something that you regret ; if your friends are getting out of control then tell them to do the same.
If you have said/done something to insult them or hurt them, then you should obviously apologise and learn from your mistakes. Think to yourself, nothing good came out of doing that so I won't do it again. However, if you truly believe that they are being unreasonable and maybe being a little too sensitive, then sit down and calmly tell them that. Don't be nasty though, even if you are mad at them. Be as polite as possible so if they accuse you of being rude then you know that you weren't being rude.
The worst possible action you can take is to gossip about them or the situation.
99.9% of the time it will get warped out of context and they will always find out about it which will just upset everyone and worsen the situation.
Releasing tension is the most important thing about reducing the impact of an argument. It's like tugging on a spring every-time there's a dispute until it springs back violently, turning into a heated argument that can permanently scar everyone. To release tension, every-time a small dispute or a disagreement occurs you should just confront it. Talk to them about it because if you don't then all the disagreements will build up and create more tension.
The key thing is to take a step back and take a look at the situation, it's not always a case of who's right and who's should be blamed for it. It's a case of figuring out how to solve the problem and making sure it doesn't happen again.
Thank you and good luck.