Revise first what is both important and unstable. Do not divide time equally across the whole syllabus simply because every topic exists. Prioritise weaknesses that carry significant marks, appear frequently, unlock other topics, or keep producing the same errors.
Use recent marked work rather than memory alone. Separate topics into secure, shaky, and failing; then begin with the failing areas that have the greatest downstream effect. Once a topic becomes reliable, reduce its share of active revision and move the time to the next bottleneck.
Use Revision Triage — What Should You Revise Next? for the deeper method, and the Study & Learning Methods Hub for the wider revision system.