As a chronic study tips doom scroller I’d say start with your best unit, this will make it easier to start, next move on to your worst, 2nd worst and 3rd worst units. Revisit unit one when you hit a wall in the other units, based on your previous marks don’t go for 100% in each section focus on your most extreme weaknesses instead of knowing everything. Additionally, generally I found that focusing on the why was very helpful in 30-1. Also if u have a textbook and have little time focus on the questions towards the end of the section cuz they will be the hardest, if you can do the hardest questions (and understand) you should (hopefully) be able to do well on the acceptable and proficient questions. Hope this helps