After each practice set, record the question identifier, your wrong approach, and the correct principle in one or two lines. Tag errors as concept, careless, or time pressure so weekly analytics stay honest.
Revisit tagged items on a schedule: careless mistakes after one day, concept gaps after three days, and integrated mixed drills every two weeks. Pair the log with a formula sheet you maintain yourself—writing reinforces memory better than highlighting PDFs.
Over time, your log becomes a personal textbook weighted toward your real weaknesses, which is far more efficient than rereading entire chapters.
What to log beyond the answer
Note the method you attempted—substitution, elimination, or direct formula—and whether the error was in setup, calculation, or reading the question. That triple tag tells you whether to drill concepts, arithmetic, or careful reading.
When to retire a mistake
After three correct retries in different contexts, remove the item from active review. Keeping every old error “just in case” dilutes focus.