A carpet runner on the stairs and art!!!!!

Yes, art. For interesting options you may want to consider what can be done with even your own artwork. Virtually anything that you can paint, draw, or photograph can be transferred to and kiln-fired on porcelain... see the photos on my Houzz page for ideas

Carpet and frames at wall!!!

What about a simple patterned large scale textured wallpaper on one side....with artwork framed with matching or same colored frames

stair runner would be nice and a hanging paper mobile. Look on etsy or go to a gallery for art! Many many options!
You could change your wall light on the left to some sort of spot light and direct it wherever you like!

I am voting for stair treads or good runner on them. color block the front facing wall and new lighting. ambient sconces (in your style) and alternate LED stair tread lights. If it's a dark staircase, these will help make it inviting. You can paint the handrail a bright color (or your choice) also liven it up. I will look for some links to post for you.



:=)