One specific example I can give you: Women find it important that you have clean, well-groomed hands. This is not intuitive or obvious to men at all, unless you know.
But I think the main problem is not necessarily the lack of information, but a more a mentality change. A lot of the men think "She has to accept me for who I am". That might be true, but it's not really relevant. You have to show what you can offer in a relationship. A woman doesn't start a relationship with you just because she all of a sudden loves you. No, she starts a relationship because somehow she gets some benefit out of that relationship. So you have to show what you have to offer. You like traveling? Maybe she wants to travel. You like a certain kind of music? Maybe she likes that music and likes to go to concerts. Or whatever.
Answering the question "Why would a woman start a relationship with you? What's in it for her?" seems a question that some men don't want to answer. I don't mean that they don't know the answer, I mean they have a problem with the question itself.
The TL;DR is to improve yourself, work on your insecurities, be emotionally open, and become genuinely not-needy. He provides a lot of specific helpful tactics.
My wife works as a dating coach, with both men and women. Men are very reluctant to listen or even try the advice, so I'm not going to try to convince you guys that you can make it work. It's not that hard actually, but most men already made up their mind on the whole dating thing. I'm sure there's plenty of "experts" here that can tell you all about how it can never work.