Attention To Detail
Buried in my 5 page syllabus is the following phrase: "Look at my webpage Course Commitments and send me an email saying hello and stating whether or not you can keep these commitments."
In a class with 30 students, I typically would get 3 or 4 emails fulfilling this task. Invariably, this is the strongest forecaster of success in my class. Students who send me this email, even before I meet them, are almost certainly going to be in the elite ~10% of students who get an A.
This reminds me of the story of Van Halen and brown m&m's. Van Halen in their contracts had a clause buried somewhere in the middle that stated the band needed a bowl of m&m's with the brown ones removed. The band knew that if there were brown m&m's, then the more vital aspects of the contract involving stage safety issues were in jeopardy of being unfulfilled to specification.
So success in college is really pretty simple from my experience. I'd advise perfect attendance, feigning a facial expression of interest, sitting in the front, visiting the professor during office hours, and carefully reading the assignments.