Key principles:
When the student is ready, the teacher will arrive.
God is faithful to provide mentors when you need them.
Hustle attracts help
Do the best with what you have and people will help you hit the next level
Pray for wisdom
Be willing to work for wisdom (Proverbs 20:5, 27:7)
Remember the concept of Mission Compatibility.
Find someone who is doing what you want to do (but is doing it at a more advanced stage/scope).
Mentorships should be reciprocal (not even, but somewhat transactional - with ever increasing reciprocity)
Surround yourself with people of all ages who share your basic life mission.
God mostly calls us to love people with the things we love.
When you need highly specific help, try to find someone who loves doing that sort of thing.
The local church is awesome.
God loves to give wisdom -- ask him without doubting.