How do I ask for an informational chat? - what worked for you?

I want to talk to people in a new field but I hate cold messages. I have been trying to stay organised about it. I want advice, not a job directly.

I asked what they wish they had known at my stage. People enjoy answering that.

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