I feel like I'm constantly trying to evaluate if I'm being too tough or too friendly, and I'm not sure how to recognize the truth. And I think it varies by employee.
Very much. I come from a creative writing and performance background where people are constantly giving each other feedback, and eagerly looking to edit/improve their work. In that world a lot of people feel like what they are doing isn't ever perfect and welcome suggestions. In other industries this is ... Not always how people feel. You can't help everybody, and you won't be the right boss for every person you meet.