Sit at somebody’s feet
Definition 1 of 2
Pro Tip 1/3Observational Learning
Use this phrase to express learning through close observation, not formal education. 
I sat at the feet of the head chef to understand the nuances of French cuisine.
Pro Tip 2/3Metaphorical Presence
It's a metaphor; you're not literally sitting down. It shows deep attention to a mentor's ways. 
He sat at the feet of the master carpenter, absorbing every detail of the craft.
Pro Tip 3/3Respectful Pupil
Highlights a respectful student-teacher relationship. 
As an apprentice, I sat at the feet of a renowned novelist.