Is there a better, more canonical way to leave positive feedback, other than opening a Github issue?

For projects that have gitter/slack/chat, I've jumped in and said thanks. I've also considered sending thanks through the email addresses provided in package control (although it seems a bit weird emailing strangers, especially when you're not explicitly seeking a response). Starring a repo is also an (admittedly small) way to show thanks. What are some other ways to reach out?