Describe someone in positive terms but then add a negative twist.
Also describe someone in negative terms but add a positive twist.
From Dragon Writing Prompts
His confidence made him handsome but the scar tore across his face from his brow to his chin.
Lady Adelle nodded in agreement and held her hand; the glint in her blue eyes chilled the queen's heart.
He had the kind words of a saint and the cold detachment of a bird of prey.
His hand, cold and gray from the grave, reached down and picked the blade of grass, as in rememberance of warmth and sunshine.
She rocked back and forth in pain and made her decision to continue.
Her silver white hair was yellowing, but her mind was sharp and strong.
This was a lot harder than I thought it would be.