Hi , I just finished my A2 psychology and got overall an A which is an improvement from me from last year. However I was the last year to do the old spec, so I can give you some tips in general since the new spec is a bit different.
definitley use loopa- he has great resources - they are long but try and formulate into your own notes so you can understand better for yourself.
purchasing CGP is good - or even the A2 textbook to have at home, our teacher gave us a copy to take home- always read beforehand and Extra research is sooo vital for psychology especially if you dont like the study they give you! (that really helped me)
a good way to remember studies is to use acronyms or some way of remembering them easier, since there will be a lot to know for the exam
good luck tho!