Ask HN: Methods for (nicely) encouraging self-driven problem-solving for others?

I'm wondering what ways some other senior/lead people help encourage other engineers/developers to improve their self-driven problem-solving without coming off as combative or dismissive?

I'm currently tasking 5 other developers with a variety of tasks, which I am comfortable doing. My current struggle is to encourage my team members to do some self-learning or training when coming up to a problem that they cannot solve. The big concern is coming off as overly combative or dismissive to legitimate issues that arise day-to-day, but I am simply too busy to help diagnose simple errors.

I absolutely don't mind helping solve problems, and I want to encourage open dialog among team members and myself. I am currently struggling with people coming to me with minute problems that can be solved with a simple search in either our knowledge base or their favorite search engine.

Any tips?