1-restyle your bookcase
2-good lighting changes everything
3-paint the ceiling a different color
4-dine better replace your dining table with a more intimate one and get new ornaments
5-instead of stripped wood use wood panels
6-instead of curved paintings or installations get squared ones
7-get things with angles to give more depth to the place for example the piece in the Image above on top of a book.
9-nude colors should be dominant in a living room and have a bit of a color splash with a book or a throw.
10-add candles to the lightening you already have to set the mood.