Art work, plants, a larger rug if possible. The picture below show dramatic large art work and lots of symmetry in the placement of the lamps and tables. Also note the large size of the rug, so that all the furniture is resting totally or partially on the rug. This pic sheers as you do and maybe consider adding chrome pieces. Personal taste though, but consider basic concepts in this room and apply your personal taste in artwork and furniture and lamps.

This image is different in that it has just the two colours, the blue and creamy white. Again the symmetry of the three pictures (I think there is like four, just not showing the fourth one) Not sure about the two lamps side by side here though.

This image shows a large phot as well, and a mural might an option and more economical than artwork. But artwork, larger rug will definitely add interest to your great space and furniture. Choose pieces and colours you love.

I think I am repeating here, but art, plants , pillows in a color you love. Candle holders, lamps, books and yes a different rug. Where are your tables?

thanks a lot you've really helped