I learned quickly, as I tell my graduate students now, there are no answers in the back of the book when the equipment doesn't work or the measurements look strange. ↗
My attitude toward graduate students was different, I must say. I used graduate students as colleagues: I gave them the best problems to work on, and I encouraged them. ↗
You are almost not free, if you are teaching a group of graduate students, to become friends with one of them. I don't mean anything erotically charged, just a friendship. ↗