I'd suggest you emphasis more of your time reading and "understanding" the contents of F8. Practice more past questions and be in a practical mind-state when answering the questions.
Also, I think you should download the exams expert app. Very helpful on the important bits of the paper.
Regarding F9, I'm yet to take that in December and I'll go by the golden rule of passing ACCA papers, "practice more questions".
Hope this helps.