Ask HN: What are some non-technical and non-soft skills I should pickup?

Hey HN! Just curious what kinds of skills you think are worth really picking up and learning that can help with your career that are not technical but are still more than soft-skills (i.e., skills that aren't the standard interpersonal abilities, communication, style, etc).

What non-technical skill have you picked up that helped significantly more than you had expected in your career?