So everyone talks about how to demonstrate high value, bu what exactly is demonstrating low value? Like what are the things to never say?
Also, for all I know high value is being the leader of men, pre-selected by women and the protector of the loved ones.
Could you expand please? Thank you.

There is a lot of material on this that already exists. You could write 10 books on each of your questions. Rather that rewriting these, let me direct you to YT where you can search these ideas and fill yourself in a bit.

But in broad strokes, to me, DHV is to display attractive qualities, DLV is to do the opposite. To act needy, inexperienced or stupid are definite DLV.

DHVs are attractive qualities such as humor, mystery, alpha-ness and providing competition.

DLVs are unattractive qualities such as neediness, predictability, inexperience and inflicting boredom.

But as mastermind said, the list is basically inexhaustible for both.

Each woman will take each action to mean something different. who knows how them fuckers think.
They want to lead but also be led, chase but also be chased. They thrive off emotions and crave drama.

NEVER outright tell a women how you feel, ALWAYS show them.
NEVER quantify your intentions, ALWAYS keep them guessing.

It's a fine art that comes with experience. I don't claim to have it down to a tee, but if you're ever in a situation and you're unsure, post a thread and someone can lend an ear.