Hey, I go to a required lecture school, so I can tell you what I do.
Depends on the day, but I either actually listen to the lecture (if its a good lecturer or subject I'm very interested in), do the earbuds and 2x speed on other lectures (or sometimes pathoma/sketchy/BB), work on my research (write papers, research literature, etc). I have found I have a hard time reviewing old lectures/flashcards or whatever in class because I get distracted by the lecturer talking, and I'm not one of those people who listens to music while studying.
For M2, I'm planning to sit farther in the back so I can do earbuds and listen to other stuff more often (this year I felt too close to the front to do it all the time. Some profs care, some don't)
However, since you are gonna be an M1, I suggest just going to class and trying the lecture thing at first, see how it goes. I remember being an incoming M1 and reading all the stuff people do on here, then trying it out and not understanding how you could possibly learn anything from 2x speed lectures, not understanding how anyone finds time for extra resources, etc. Weirdly enough at first I found my time best spent actually paying attention in lecture. Now I love 2x speed and having a greater percentage of time learning coming from outside sources. You eventually learn what you need from lectures (and develop an ear from someone speaking double fast) and I know what I need to get from the lectures to pass tests and have plenty of time to add in board resources.
If you are like most people, its gonna take at least a few months to get your study methods/style down. Just work hard and keep tweaking what you are doing until you find your rhythm. Also, people have different opinions on this, so you do you, but I wouldn't go too crazy with extra board resources at first. Don't try to review/learn stuff in them until you're going over that same info in class. Do use them alongside classes if you have time. I felt like I didn't at first, but then found that if I cut out a pass of lecture material and then used that time on pathoma, sketchy, etc instead my grades didn't drop and I probably learned better.
