"The secret of change is to focus all of your energy, not on fighting the old, but on building the new." - Socrates
There are concrete strategies you can use to earn better grades in your classes. Regardless of what your study habits have been in the past, new classes present new challenges and you need to use new strategies to overcome them.
Some key strategies are:
Attend all classes, come prepared to class, and complete assignments on time.
Balance major classes with GE & elective classes.
Exercise the 2:1 ratio for studying. Study at least two hours for every one hour that you are in class.