Review the ledger as a record of economic events. Start with unusual balances, then trace them to source documents. A debit payable might reflect a vendor overpayment. A credit bank balance might be an overdraft. Neither should be changed merely because it differs from the account's normal side.
Use fresh figures to distinguish posting errors from classification errors. A duplicate entry preserves equality and overstates both sides. An omitted balanced entry preserves equality and understates activity. A transposition may disturb the totals. The purpose of the review is a supported set of balances, not simply two matching column totals. Record a correction only when the evidence identifies what went wrong.