Making a hidden light and elegant atmosphere in your home need some work and some knowledge. This is a project that takes time, tools and skills so the effect would be as you wished. The required steps for this project are: Marking the wall, Installing the light strip, building the cove, fish the new cables, completing the connections, installing the crown.
It seems hard and complex but if you follow the instructions given in the link bellow this is achievable project for you! Take a look.