Learn English – Read ( Beautiful + Interesting ) stories

A common term for what the OP describes is, "Her complexion was flawless." (a Google search for flawless complexion returned about 1,110,000 results)

flawless adjective: without any blemishes or imperfections; perfect. "her brown flawless skin"

synonyms: perfect, unblemished, unmarked, unimpaired

If the boy is still a child, pre-adolescent, he can be described as being beautiful.

He's a beautiful baby/child/boy

sounds perfectly acceptable to my ears. The boy himself might object to being called beautiful once he turns into a teenager, as it is usually considered an effeminate term.

For teenagers and adults, the genderless adjectives good-looking, and attractive are the safest and best-known options. They can be used for young and “mature” people, both men and women.

Good-looking as defined by Oxford Dictionaries (Chiefly of a person) attractive.

Damon looks to be on the fast track towards becoming one of cinema's brightest bad boys. He's a good looking guy who can look brooding with the best of them, bringing to mind James Dean and the young Marlon Brando
_{Michael Redman}

I'm tall, slim, blonde and, so I'm often told, a good-looking woman. I know how lucky I am. But there are downsides to being pretty…
_{Samantha Brick}

attractive (Of a person) appealing to look at; sexually alluring:

• For I suddenly seem to be encountering a new generation of stunningly attractive women in their fifties.

• Footballer David Beckham is one of the most sexy and attractive men on the planet.