Give English some time almost every day. Hopefully, you have finalized your subjects. The next step is selecting quality books. Read the syllabus given by FPSC. First give a general read to a subject and then make your own notes during revision. In my opinion every subject does not need notes. It will help you in revising during exams.
Past papers should preferably be consulted during revision.

Set yourself targets and prepare a time table till December.

I feel a subject of 200 marks takes around 45-50 days for a good grasp. Preferably, don't cover too many subjects at the same time.

There might be periods of despair and distress when you doubt yourself and your preparation. The key is to keep going.

I am no expert but these are my little observations and experience.

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"If we don't stand for something, we may fall for anything."