In that sense it is no different to other professional attributes required in your field. If you want to get better at it – you have to spend time on it.
There are many of us who could improve our leadership in one way or another. You might find it helpful to read this pamphlet when you join a new organisation, are promoted or take on new responsibilities. Six months later it may be worth having another quick read to help review and refresh your leadership knowledge. It might also be able to give you personal guidance if you are confronted by a particularly difficult leadership challenge.
Improved leadership leads directly to improved effectiveness. We have recognised the gains of the Scientific Revolution, the Industrial Revolution, the Social Revolution and the Computer Revolution. The next step up in performance needs to come from a Leadership Revolution.