Good advice in this article for people who (like me) are asked regularly whether someone can ‘pick your brain’.
If you decide you do want to give advice, do it on your terms. If they ask to meet for coffee and you don’t have time, send an email instead. If they ask a question that requires a novel-length answer, address one part of it, or send them some helpful links. Don’t fear being explicit that you didn’t have time to answer in full by saying something like: “Thank you for reaching out. Your question requires an answer that I unfortunately do not have time to fully address due to my work. However, you might find the following books/links/thinkers/YouTube videos helpful.”
Given I live in the back of beyond, most of my initial meetings are online, which makes life easier. I give people 30 minutes for free, and then that sometimes leads to them asking me to put together a proposal for them.
What I particularly like about this article is that it encourages readers to find ways to give back to their sector / profession:
Once you’ve created boundaries around when and where you’ll provide help on demand, you can begin looking for other, more expansive avenues for giving back. This can include devoting your time speaking on panels, at schools/universities, on podcasts, or at workshops for free if it’s a cause or audience that would benefit from your knowledge. Though beware of the requests that can often follow on from such engagements, and refer to the third step when answering them.
One thing that’s not mentioned in this article that I’ve found can work is if you offer a ‘critical friend’ service. This is basically billing them for a day’s work at your regular rate, from which they can draw down time for advice when they need it.
Source: Quartz at Work