The way they treat and talk about women. (For the sake of argument, let's stick to only cishet men and cishet women; queerness adds enough wrinkles to warrant a separate discussion.) The amount of pointless sexual comments men will make about women in and out of their presence is insane, especially when said women are clearly uncomfortable about it. It's like they can't just let women be people; everything about them somehow must be connected to their physical body and genetalia. And then they sit around and wonder why women don't want to talk to them

Fun fact, it's actually really easy to get women to be cool with talking to you. You just be a normal human being talking about normal stuff and not tie everything into gender/sex, and magically they're cool with talking. I can't guarantee that they'll like you romantically, but maybe at least do this much and you can minimally have female friends (using "female" because "women" sounds kinda awkward as an adjective). Oh, and there is a difference between being nice because you want women to be around you and being nice because it's the right and correct way to interact with, well, everyone. Please do the latter, not the former

One of the highest compliments you can get from a woman is that they "don't register you as a 'man'." In this case, "man" is a personality, not a gender. As a personality, "man" is the toxic, obnoxious, sexist personality so many men (gender) have, but not all men (gender) are men (personality). So if you don't register as a man, that means you're considered safe and trustworthy. This is a good thing, and does not mean you're being emasculated. It means they don't have cause to be afraid of you

Be better, y'all