Better way to handle 'auditing' columns such as created_by, created_dt, last_updated_by, last_updated_dt

Hi guys

In a previous question I made the below comment, which resulted in feedback that there are better ways to handle these values, to include splitting them into a separate table.

As a general rule any table I design that has data entry, I'll add four 'auditing' columns to it that populate via INSERT and UPDATE triggers:
  created_dt  -  datetime - of the entry
  created_by_id -  varchar(30) - SUSER_NAME() of the person creating it
  last_updated_dt  -  datetime - of any insert-update
  last_updated_by_id - varchar(30) - SUSER_NAME() of the person updating it.

Points for advice on a better way to handle this.

Thanks.
Jim