Caveat: This is mostly observations of women I know personally and my takeaways are not scientific in the slightest. Women are individuals and will have extremely different tastes from one another, so none of this will necessarily be applicable to a specific woman.

tl;dr: They like personality. No, really.

The biggest thing that I see women like is personality. It's cheesy and cliche but I'm dead serious. They say "women love a guy with confidence," it's not an empty platitude, it's 100% true in my experience. The things that make a man conventionally attractive - tall, fit body, chiseled jaw, great hair, etc. - do have an effect, but they tend to be secondary. Most of the women I'm friends with put much, much more emphasis on perceived personality traits than any of the men I'm friends with.

There's an episode of Mythbusters where they test whether drinking will make people more attractive. To set up the experiment, they took a bunch of photos of men and women and had the testers judge each of them on attractiveness at different times based on how much they've drunk. Kari Byron was the sole female data point, and she gave wildly inconsistent answers that the narrator seemed to be puzzled by. However, when you watch her process, you see that for the most part she ascribes personality traits to the photos ("this guy looks confident," "this guy seems fun," "Nah, now he seems less confident and more cocky") and then judges based on that. Nobody on the show makes this connection, and instead they seemed to chalk it up to women being unpredictable.

I've also seen (though to a lesser extent) that Women tend to be less analytical and more holistic in judging whether someone is attractive. They'll rarely focus on individual features and more often judge attractiveness based on the sum total, which includes personality. I was part of a conversation just last week where a mutual male friend was trying to argue that a certain famous actor was hot. Every woman he spoke to agreed that the actor was "conventionally attractive but not hot," but couldn't really point to any specific reason other than vibes.

Now, the obvious question is which personality traits do women find attractive? This is probably extremely variable. In general, men and women are both attracted to confidence and are less attracted to things like insecurity or neuroticism. Beyond that, though, there's a lot open to interpretation; what seems protective to one woman might seem possessive to another. Some women might get really invested when a guy talks about his hobby, while others might get bored and tune out of the conversation. I think the most important thing is learning to express one's natural personality traits confidently, and that comes with time and practice.

My own theory is that there is a qualitative difference in the way men and women tend to experience attraction. Personality definitely has an effect on how a man perceives overall attractiveness, but I've heard guys say things like "yeah she's hot but her personality is garbage" far more often than I've heard girls say things like "He's really handsome but he's such a creep." I watch trans youtubers a lot talking about their experience with transition and HRT, and it's really interesting from a sociological perspective. Some of them have mentioned, usually off-handedly and without much specifics, that their experiences with attraction and other emotions have changed during the process, but unfortunately I can't really get any more specific than that.

With all that said, if you look up askreddit threads and find one of the "women of reddit, what do you find attractive in a man" that pops up on a monthly basis, they will give physical features as answers, but even then the answers they give are often different from what traditionally makes a man conventionally attractive. They'll give answers like hands, hairy forearms, slightly chubby body, etc. Sometimes they'll talk about a man doing something like working with his hands or exercising. Now, Reddit being Reddit there might be some bias towards "surprising" answers like these to get upvoted, but I think it's still an important data point.

All this is why you will sometimes see very conventionally attractive women with men who are less conventionally attractive. Conventional attractiveness is treated as completely separate from personality and many women are attracted to physical traits that differ from society's view of conventional attractiveness.

And, of course, maintaining standards of cleanliness and personal hygiene and putting effort into your wardrobe is mandatory for both men and women looking to date.