I've taken my fair share of university exams in the last three years so I think I'm pretty good at it.
All of my classes are math and engineering related so I can't help you with creative writing (or technical lab briefs for that matter...).
From my experience:
1. Don't cram or do any stupid shit like stay up all night trying to "study". If you don't get the material in at most two hours then try again another day, obviously this means you should practice the material long before any exams are actually happening.
2. Get really good at memorizing. Even if you don't fully understand the concept, if you can remember the procedure to solve a problem, just do it. If you're using units, make sure to rewrite the units each time because it helps to keep things straight.
3. The average course has anywhere between three to five exams, professors usually drop your lowest exam, if the class is difficult it's very possible you can still get an A even if you get 70s and 80s on the exams.
4. The final exam is what they want to see the most improvement on. If your final exam grade is high, then you can expect your final grade to be pretty high as well if they see you're doing all the assignments.
Let me list exam grades for some of my classes with my overall grade; I'll list them from easiest courses to hardest courses. I don't know my final exams scores for some classes, so I'll place a ?? there instead. I also can't remember the scores I got on some classes like Calculus I and II so they aren't there.
Probability : A- (thanks mafia)
75 90 95
Linear Algebra : B+
85 92 ??
Differential Equations : B+
80 94 89
Chemistry I : A
92 95 99 ??
Physics I : A-
78 90 ??
Physics II : A-
89 84 ??
Calculus III : A
64 85 92
Digital Logic : A-
74 75 78 85 ??
Electrical Circuits : A
100 78 75 99 81
Case in point, even if you get pretty decent marks in easier classes, because the exam averages are so high you may not be guaranteed that A.