As I've progressed into more senior roles, I have been lucky enough to mentor quite a few new and junior designers. My goals when mentoring junior designers are:
• Help them get up to speed on the complex space we're working in
• Give them as many of the tools from my product toolbelt as possible
• Work collaboratively so they can learn the process rather than just giving them answers
Priming for the Problem
Depending on what projects I have available, I usually start by having someone shadow me through brainstorming meetings, user observations, and product meetings. This gives them a strong platform to observe and learn vocabulary and important concepts. It also lets them see an inside look at how I structure things like interview questions or write surveys before they're expected to do it on their own. After most of these meetings or observations I like to have a debrief with them so they can ask any questions, and I can reiterate why I did things a certain way in a meeting or for a certain audience.
Once they've got that, or if they're a more experienced designer, I move quickly to assigning out work to them such as writing questions or recruiting users for a test, so that they can get practice doing it on their own but I can still guide them with feedback.
Feedback
I try to use open ended feedback and questions as much as possible. I want people to practice explaining their work with out feeling like they're wrong or need to defend it. Questions like, "What are we trying to learn with this question?" or "What's the strongest point you want me to walk away with?" make for better conversation and teachable moments than simply walking in and telling them why something is wrong and how to do it. And I've often found that with fresh eyes they may have a different perspective than I do and can help me do better as well.
Creating a Culture
Long term, I like to help build an open environment of support and collaboration across the team. This provides stability as team members change and is critical to enabling open critiques and discussions of designs and ideas. That includes critiques and feedback of management above as well. An important skill I've learned is how to give critical feedback to my managers and other more senior team members, which is important so for them to continue to learn and grow as well. That kind of openess and transparency helps establish a culture for all of our designers to grow and thrive with their peers.