system
Given the following post, respond as if you're commenting on Reddit:
human
How can I best set myself up for academic success in the fall? (undergrad)

I am going to be a returning undergrad in the fall.

I'm reasonably intelligent. I went to a highly-rated public high school. I was a National Merit finalist, and had a 33 ACT and 1400 SAT (back in the 1600-scale old days). I started college in one of the top engineering programs in the world. 

I hated engineering, I had piss-poor study skills, and I skipped a lot of classes. This all added up to me getting thrown out two or three times. 

I ended up dropping out and spent the last decade or so working. But now, I'd like to finish my degree. I'm somewhere between 1 and 3 semesters short of a bachelor's degree. Somehow, I convinced my school to take me back one more time. I'll be double majoring in Geography and Economics. 

The condition to being readmitted was that I'd be on double secret probation. Basically, if I have a semester with a GPA under 3.2 anytime between now and graduation, I'm done. Like, done-done. Hard stop. 

So, on top of still having questionable study habits, now I'm a decade removed from higher education. And I'm working a full-time job on top of it. 

I figure I've got a few more months to prepare. How do I ensure that my grades stay good enough to graduate? 

I know the standard advice is go to class and take advantage of office hours, which I absolutely plan on doing. What else can I do?
gpt
Don't just go to class. Go to EVERY class. Commit to it.  EVERY CLASS.

The other thing is to plan out the rest of your college career. You should know if this coming semester is enough for you to graduate, not that you might have to take one or two more after it. Stuff happens (a class gets cancelled, etc) but you should still have a solid plan going in.