A man who was with him became suddenly aware that one more backward step would mean a fatal fall. Quick as a flash he made with his own brush a sweeping stroke across the picture. Someday we shall thank God for every loss sustained in this life, for every shattered idol, for every disrupted plan. Be more or less specific. Understatement is always best.
Exaggeration is a billion times worse than understatement.
Analogies in writing are like feathers on a snake. The passive voice is to be avoided. Go around the barn at high noon to avoid colloquialisms. Even if a mixed metaphor sings, it should be derailed. Comparisons are as bad as cliches.