One should never generalize. Tell me what you know. Comparisons are as bad as cliches. It behooves you to avoid archaic expressions. Avoid archaeic spellings too.
Understatement is always best.
Exaggeration is a billion times worse than understatement. Analogies in writing are like feathers on a snake. The passive voice should not be used. Go around the barn at high noon to avoid colloquialisms. Don't repeat yourself, or say again what you have said before.