Cold messages to people in my field, do they work? - what worked for you?

I want to talk to people in a new field but I hate cold messages. There are 18 people counting on me, so I am trying to be careful. Some people reply with short answers.

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

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