Thanks for the great question, Dan. I think a lot of people have to learn the soft skills along the way, as well as tangential, but crucial, hard skills (i.e. finances, contracts).
I don't really have a definitive answer for you, but here are some soft skills that I've learned in my career and would encourage others to learn:
- Really listening
- Reserving gut reactions and judgement
- Negotiation/civil argument
- Learning from everybody in every situation
I'm sure there are more, but that's a quick dump of ones on the top of mind at the moment.