Responding to emails from strangers outside academia asking you advices
Why don't you start a blog? An FAQ and a few posts might be enough to address the vast majority of questions without costing you a ton of time.
You can then refer any inquiries to the blog. In time its popularity will grow and people might go directly to it instead of sending you emails.

You can highlight you research, grow your professional network, lead to collaborations AND save time by not having to answer the same question a million times.