Well it depends on your university. I was once a student of so-called best university of my country and got utterly disappointed with it. So the best secrets about being A+ grade student is to choose A+ grade university. And in my country there is only one university which bears this honourable title. But today even this noble university became bad. So only one way to be student of this university is to create a time machine and move to 60's/70's when this university was truly aristocratic and noble. It's easier than trying to pass entrance exams.
Nothing personal, really