Hey, when I was revising for my psychology exams last year I found it helpful to summarise everything in one topic down to a side of A4.
For studies, I found it helpful to pick out key info a squeeze it all into a sentence.
e.g.
Peterson and Peterson's study of duration in short-term memory: They conducted an experiment where 24 participants were asked to recall trigrams at different intervals, during which the participants were instructed to count backwards in 3s to prevent rehersal, the intervals of time ranging from 3-18 seconds. They found that info decays quickly when rehersal is prevented - after 3 seconds 80% recalled the trigrams and after 18 seconds 10% recalled the trigrams. On average the duration was 20secs.
Shortened: Peterson + Peterson (STM Duration): trigrams Ps count backwards. 3 secs 80% 18secs 10%. info decay
Do the same for the evaluation.
After you have done this for a topic print off as many past papers you can and do every single question there is on that topic.
I got an A at AS, so this technique definitely helped me! If you're struggling with it at AS I wouldn't recommend doing it at A2, its a lot harder!
Hope this helps!