You make the product to the procedure and write down exactly what you did, as you do it — not afterwards from memory.
You execute steps to the master batch record, perform line clearance and in-process checks, and raise deviations when reality departs from the procedure. Contemporaneous recording is a requirement rather than a habit: a record completed at the end of a shift is a reconstruction, and an inspector can usually tell. You also hold the authority to stop — when a parameter moves out of range, when the procedure no longer matches the line, or when something looks wrong and you cannot yet say why.
You are the first line of the state of control — most quality either happens or is lost at your step, and no amount of downstream testing recovers it. Whether problems surface early enough to be cheap depends almost entirely on whether raising one is safe to do. The organisations that hear about problems first are not the ones with better procedures; they are the ones where stopping the line has happened, recently, without consequence to the person who did it.