Whenever I think of skills, the first one I think of is people skills. I think that is the most important type of skill-set to have. Knowing how to treat and talk to people is beyond important in the workplace. When you know how to talk and treat people, it really doesn't matter what kind of product you are selling. When you make it about the person and not the product, walls fall down. Learning how to read people and get a feel for their personality has really helped too. It's a shame more management teams don't take the time to learn and teach this to their staff.

I hope that helps!