Cold messages to people in my field, do they work? - any advice?

A friend suggested informational chats and I do not know how to ask. Any experience at all would help. I want advice, not a job directly. How do you phrase the request?

I wrote three short lines: who I am, why them and a small ask for fifteen minutes. About one in four said yes.

Thanks for writing this out. I went through something close to it 5 months ago, and it got easier once I kept a simple log of every call and form.