Developing competitive skills such as adult education at par with the industry is the key to a career growth and a prospect for better job opportunities. If you want to see more doors open for you, you might consider learning what is the next best thing in your field of work.
Suppose one work in a technical field, then learning new programming languages is most desirable. If one is inclined towards management or business analysis, then knowing more tools can augment one’s existing skill sets. I am a technology consultant, I recently completed a course on R Programming from Coursera and am planning to pursue a very interesting course on Machine Learning.