I read this book called "Running Lean" by Ash Maurya! Wonderful framework for doing initial interviews.
At first, I published a landing page on https://iseloapp.com and I started contacting my professors and their peers to get some time from them for in-depth interviews. To understand their everyday professional routines, the problems they face, what kind of tools they use... etc.
I created this template to jot down their response.
I could learn that,