How do I ask for an informational chat? - any advice?

I want to talk to people in a new field but I hate cold messages. I want advice, not a job directly. What did you ask?

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

Follow up with a thank-you and a short update. One of my chats led to a referral a month later.