Improving Grades

So all my exam results have come out and I haven’t achieved the grades I’ve wanted which is disappointing but also a time to reflect and try to understand what I should do differently. I am currently sitting around the high 60s low 70s for most of my subjects but want to push that to high 70s and 80s over the last year of my degree. So my question is; what are your techniques and tips?

For some background information - I am a second year commerce student heading into my final year majoring in Economics & Finance.

In semester 1 I look to be doing Derivatives, Investments, MicroEconomics & a breadth maybe Calc 2?

Thank you all in advance.