Sally looked at Bertha. The redhead smiled back at the blonde. The younger sister laughed and the other laughed, too. Mr. Johnson laughed the loudest.
Sometimes, nouns are replaced with noun phrases, such as in the example. But, who’s blonde? Who’s redheaded? Is Sally or Bertha older? Who’s Mr. Johnson? A teacher? Friend? Relative?
If a character has a name, use it. Narration needs to come across as natural; when was the last time you referred to someone you knew as “the happy blonde?” I hope it’s never, because no one thinks like that like. You don’t think of your brother as anything other than “my brother” or by his name. Characters are people. They think like people.
When a character’s name is replaced by a descriptive phrase, it comes across as amateur. It is a quick way to tell the reader things like hair color; good writers can fold that sort of exposition elsewhere. Early on in a book, call a character only by their name as thought of by the narrator.
Sally would not think of her father as “Mr. Johnson,” or “Mike.” She would think of him as “Dad” or “my father.” The same goes for 99% of people. She wouldn’t refer to her best friend as “my best friend,” unless she’s under the age of fifteen. That is a lesson in how a character thinks regarding their age.
In writing, be precise, direct, and clear, all the while maintaining voice and style. Once you’ve mastered writing while juggling live snakes, you can call yourself the greatest writer of all time.