Hey. There's a couple of things I learned.
First, and this is the most important one, practice being completely chill. Don't get emotional no matter what the discussion is about. It doesn't matter how important the topic is to you, just don't get mad. This will genuinely make you like 10000% more likeable to everyone.
I'll give you an example in my own life. I've been an animal rights activist and ethical vegan for years. So I have a fair bit of emotional investment in it. One time I went to a dinner with a friend for their work and I am not kidding you the entire meal was two hours of absolutely everyone constantly shitting on me. And I won't elaborate but their comments were extremely rude and highly inappropriate. I could have justifiably put my knife and fork down after 10 mins and walked right out. But I just sat there completely stoically detached from it and matched everything they said with a grin and a witty comment. I've met many of these people since and we all get on great. Most of them are nice but got caught up in the groupthink and easy target. Two even apologised. And when they apologised, I didn't use it as an opportunity to shit on them, I thanked them and complimented them for doing so.
Adding on to this, just avoid offering your opinion on controversial things where it is at all possible. Make vague statements like "it's a complicated topic and I'd want to read and think about it a lot more before really offering any opinion."
My advice is to find a discussion on a topic you are really involved in, whether it's a political, religious or broader philosophical ideology and try read it without getting emotional. You'll also find you'll be able to tackle discussions better with a cooler head.
Now you might say, "won't people like/respect me if I'm passionate about my beliefs?" Nine times out of ten, no, they won't, unless what you're saying completely coincides with their beliefs. Do you feel all warm inside watching fascist dictators give passionate speeches? (maybe you do, but I imagine you get the point).
Listening is one of the easiest ways to become likeable. Listen, don't comment much and make simple empathetic statements like "I'm sorry". I've thought a lot about why people discuss their problems with others. Most people think it's because this person wants constructive, emotionless advice. But I don't think that's the case. I think if people want advice, they'll literally ask for it. What I actually feel people are doing when they tell you their woes is just processioning their thoughts for their own sake and hoping for some basic empathy and warmth in response. Next time someone tells you they have a headache, don't say "Did you take a paracetamol?" or "what do you think produced it?". Say, "What does it feel like?" followed by "is there anything I can do for you?" and give them a hug if you're comfortable with them.
This website is a perfect breeding ground for practising this. Take any post where someone is outlining their grief and instead of trying to give unsolicited advice, just make an empathetic statement. This is what the most likeable members on this board do. I can think of their names off the top of my head and typical variations of comments they leave.
Another piece of advice: don't make jokes at others peoples expense and especially not in front of others so that they become the center of a joke. Before you make any joke ask "could this have the potential to upset this person?". Usually if you're mocking their appearance, lifestyle choices, friends/family or beliefs it's just a bad idea.
I would say that the internet is a bad place to get feedback. People can lose it because they're copmpletely misinterpreting your emotional demeanour and intent of what you're saying. You can make the most banal comment and people can melt over it. So practice this stuff in real life and see how it goes down.
If you want more advice, feel free to PM me. I know it's vain to say but I'm genuinely very well liked in real life.
