I'm only applying to PhD programs, so I'm not sure if the protocol is the same for master's programs! I've emailed a few professors who I would want to be potential advisors to express interest in their research, confirm if they are accepting students for this cycle, and mention my own research interests. There isn't a set way to contact people. Try to keep things professional, brief, and make things specific to each person to avoid looking like you just spammed a bunch of people. I've gotten a pretty big range too! I had a few people seem excited, a few polite responses, and some that didn't answer. I think a lot of what we hear back depends on the person and timing.