When it comes to character descriptions, every author has a different approach. Some paint in broad strokes. Some describe their characters in great detail. Either way, descriptions should serve a purpose beyond painting a picture of Abs Mcgee and Dangerous Curves. The way a writer describes a character should evoke a feeling you want the reader to have about them. People are quick to judge by looks and authors should use that to their advantage.
Play with stereotypes: Describe a cliche or trope within your genre for characters whose personality and actions are nothing like what the reader would expect. Patricia Briggs described the trope of a hardened cowboy, who one would expect rode the range alone. He was actually a werewolf, who’d faced a lot of prejudice within the pack for being gay. He was also in a stable relationship with a high powered lawyer with a sharp mind. She could have gone a completely different direction, but I like what Briggs did with that.
Note only important details: If you’re going to describe a scar, let there be a good backstory to that scar. Make it plot related, and character building. That scar isn’t there for an aesthetic. It’s there to say something about that character.
Skip the blue eyes and washboard abs: Unless you’re writing a romance novel, the eye color isn’t important. Honestly, the color of someone’s eyes and hair only matters if it’s something your character would notice and there should be a story reason behind it. Readers will fill in those details themselves anyway.
Photo unknown source