I'm a dude who's pretty much always questioning myself on whether my beliefs are fair, if i'm debating properly, etc. Often regretting stuff I said not too long after posting due to noticing flaws and preconceptions in it. Probably a result of low self-confidence tbh, but I believe it has some benefits in this area. I've noticed some things I have a tendency to do that don't help my case at all, and I've noticed some other people doing it as well. So here's some things to keep in mind if you've never heard them before. If I'm correct on some of this, might help some folks out.
You should avoid phrases and words that imply that the other person isn't thinking straight or is being ridiculous. "Do you really think [X]?" at the start of a comment is a good example. Other cases include using words that stress the meaning of what you're saying to imply the person you're replying to is talking nonsense. e.g. "[X] can't/is unlikely to [Y]" vs "[X] can't even [Y]". Words like even, really, so, always, never, actually etc are often used like that, instead of more tempered descriptions. Sarcasm used in political debates is also usually a product of this, in general. I could also add some similar usages of italics and bolding, which I've done a few times on past accounts. It can often just be the natural way you talk to folks when you're frustrated with them.
The problem with doing that, is that your argument can most of the work in showing why another person's view is faulty if it truly is. The stuff mentioned above however, is more a product of the visceral reaction to seeing something that seems ridiculous. Feeling somewhat incredulous that the person you're talking to believes what they do. It's a natural feeling, everyone does it to some degree. But it's detrimental to express that when convincing people who disagree with you, as they will likely feel slighted. It mainly gains the support of those who already agreed and felt the same before the debate.
Speaking of visceral reactions though, a similar thing can hurt you in a different area, the area of being convinced rather than doing the convincing. Think of an opinion, ideology, etc that you're very much not fond of, if any. Usually, people who have that view have certain common ideas, phrases, words, etc that make you realize they have such a view. Things you would reference if you tried to imitate someone with that view.
You probably don't have a positive reaction to that stuff, might make ya roll your eyes or not take the person very seriously. However, that can often be more a kneejerk reaction to what you're reading rather than a rational one. Getting used to disagreeing with a certain view can leave you doing it out of instinct, without considering the view or the specifics much. Not leaving as an option to be convinced by such views anymore, by the end. It's fairly easy to do this, it's proven to be pretty natural for me at least. But if you would like to be convince-able by people of all beliefs if they put up a good argument, it's worth trying to keep that sorta reaction down a bit. I've personally been trying to catch myself when I feel like i'm brushing off an opinion too easily lately.
That's pretty much all I got. Hope I'm right and that it helps folks with this stuff.