Bad A level grades but revised loads?

Throughout my Aevels I definitely did as much revision as I could have but I didn't get the grades that I wanted at the end of the year. For some exams I can see why perhaps I dropped a few marks due to gaps in my knowledge but for others I definitely prepared as much as I could have done, but in the end this wasn't enough. Just wondering if any of you have tips and advice or are in a similar situation yourselves as I am now lost as to how to revise for uni exams.

If you know all there is to know on the spec for the subject then it must be that you're not applying it correctly to the questions in the exams. Maybe focus on how to answer questions correctly to make sure you get the marks.

Exam technique isn't a technicality to understanding. Being able to perform in an exam is also part of your preparation.