I use checklists, and they work. Scientists and engineers have a technique for complicated mathematics, which might work for editing sendmail.cf. Do it twice,

I use checklists, and they work. Scientists and engineers have a technique for complicated mathematics, which might work for editing sendmail.cf. Do it twice, and compare your answers. This works best when the "you" is plural, but repeating your own work the next day is better than nothing.