Ask HN: Which non-technical skills are important for Software Engineers?

I was discussing non-technical skills (soft skills if you like) and how we recruit for them with a colleague yesterday. Interestingly we were both of the opinion that they are equally as important as technical skills but that learning them is harder and therefore we should hire more for them than specific technical skills.

I wanted to ask the community, which non-technical skills do you think are most important for Software Engineers and more importantly what specific steps can someone take to develop those skills?