conference room underground lighting!

Hello guys, as the title says, I'm working on a conference room project, around 60 sqm room underground with no single window, all lights should be artificial and warm. As I'm starting to build the lighting scenario I feel it's so flat and boring with nothing interesting to look at. The client wants to see the whole space lit, so I can't work too much with intensities to create some nice shadows.

Any tips and tricks on how it can be lit, anything can be helpful (YouTube video, article, own experiences...)

Thanks