What habits should I build in the first part of my PhD? I'm a first-year PhD student in a computer science department. As is usual at this school, my first three quarters are spent rotating with different professors, finding an adviser and a research fit that I like. However, unlike previous rotations, I can see myself working in this subfield for my PhD, and I've moved from wondering what subfield I'll be working in, to wondering how to get acclimated in this field. 

I've always been a person to run an "outer loop" of self-reflection, advice-asking, and habit-forming. In undergrad, I followed a few blogs about making the most of college. However, it's been a lot harder for me to find useful advice about doing top-quality work in getting a PhD.

I hear that in the first part of your PhD, students are significantly less "productive" than in the fourth year and onward. That makes sense, and I'm becoming comfortable with the banging-head-against-wall feeling that is creeping up on me. However, I'd like to know what the three years of "unproductive" time teaches you to do, so I know what I should focus my energy on during these years.

I've heard it's important to read papers, develop a "taste" for useful problems, and hone in on a larger research question. However, each of those has a lot of follow-up questions that few people seem to talk about. Reading papers: how many? what about? what for? Taste: how do I get as many "data points" as possible in learning what's a useful problem?

Edit: I'm at school in the United States, and I'm unsure whether I'd want to go to academia, industry or run a startup. If I were to bet right now, I'd say 50% academia, 30% startup, 20% industry.
To get the ball rolling, I will offer an answer.  I will invite others to edit my answer to improve it, or write another answer.


In the early part, spend about 5 - 10% of your time looking at journal articles and other scientific literature (if you are on top of your coursework).
Form one or more study groups, if for no other reason than to get practice communicating about your subject area.
Attend seminars.
Visit office hours.
Try to keep your notes organized.
If there are foundational exams in your program, get some old exams and start looking at them, as time permits.
Find fun ways of getting exercise.