Memorising cases can be hard but there are a few methods I use to help me.
My lecturer at uni often draws pictures to help us remember the main facts of the case e.g.
Donaghue v Stevenson she will draw a snail in a bottle on the board, then when I need the case I usually remember the case being the one with the snail in the bottle.
It also works if u can remember the main facts or something strange about the case, for example
Chapman v Herse its ironic because the guys name is herse and he kills someone in a car accident...
With legislation if u can't remember the year or if it is Cth or NSW write it anyway...something is better than nothing and teachers appreciate u are in an exam situation.
I found practice essays to be useful in studying, do them within the time limit they will be in the exam. This helps you practice writing fast, under pressure and is like a form of study, I found writing things out in essays helped me remember them.
Family is quite a hard topic to study as there is a massive amount of content. I tried to learn one or two areas of the law in depth and have a general knowlegde of the others incase the question was specific but you need to see what is best for you.
Good luck and any other questions fire away