Just keep doing exercises
Best think to do is remember by heart statement of:
Consolidation of accounts
Profit margin/mark up
If you know this as a start you will find everything else as a detail to the above and it will be easier for you to make the link between them.
Hope that helps.
You basically need to find a good ACCA study provider like I use BPP and EMILE WOLF, I combine both because I get explanation from the two different aspects. Thus, I understand more and I can remember more easily
Remembering isn't the best way of learning for professional development.
Everything in your ACCA subjects are based on concepts and reasoning. If you would try to understand those reasons and concepts you would know things without an effort to remember them.