Be yourself is a cliche, I know.

Unfortunately without further explanation, it's kind of useless advice. You think "well i've been me for some time, like since birth, and I'm not a Casanova. So thanks for nothing.". And it can also be confusing when someone says it here, because so much seduction material is labeled "self improvement". Inherently meaning transform yourself, so just be yourself is stupid advice... right?

Not entirely. When someone says be yourself, they're speaking of being real. Authenticity and honesty.

You have to trust and assume that your natural, genuine identity is enough to pull girls. Assume she will like you for you. Don't fall in the trap of trying too hard to be 'cool', 'alpha', 'prince charming', or any number of the fronts guys will take on when talking to a girl they're trying to fuck.

Now, you do obviously want to be cool, alpha, charming, etc.. But it has to be real. You don't pretend to be some different identity that might be seen as more 'cool'/alpha'/'charming'/etc. You instead present your real self, in the coolest most charming most alpha way possible. You don't force and act out an identity that isn't truly yours, just to look good. You present your true identity in a way that is good.

Don't try hard to be a, let's say a character named "perfect man", as many guys (probably putting her on a high pedestal) do. If she's on a date with YOU, she wants to get to know YOU. If she gives YOU the time of day to talk to her, she wants to talk to YOU. She wants to be seduced by YOU. Not a parody of you that you force out based on things you read about women online, and inspired by your insecurities.

Who you genuinely are, is what girls who like you want. Trust and believe that. Be yourself.