With your original pictures - I agree with larger rug. But I don't agree with comments suggesting the rooms are monochromatic. They are lively indeed. I think you are just missing some accessories! Art work on the empty walls - even just a single large dramatic piece is in order. In the bedroom on the white wall, in the living space behind the sofa, in the greenish bedroom behind the two beds. Those are instant areas where you can improve. But I think your spaces are lovely and well put together. Also I agree with the comment about table lamps - some of those would really add something, and your coffee table looks so empty - maybe just one gorgeous bowl, or stack some books. These rooms are 90% done in my opinions, just need a few finishing touches. Some of my rooms come out like this because the clients are not willing to pay for those last few finish items or feel they can do that part themselves...

I have some suggestions if you are thinking budget friendly changes. Make a photo gallery with different size frames and arrange them parallel to the stairs, so you can enjoy each photo as you climb up. And for the area that will be on a level with your upper floor, try some pretty decal that will connect the photo gallery to upper level. And last, if you have budget add some beautiful hanging lights in the stairwell. Also think about repositioning your refrigerator.

I found a bunch of stuff last year while dismantling my bed and cleaning under it. There was stationery, old socks, a kitchen cloth, earrings and chew toys ... all hidden there by my dog (he being tiny could access its deepest sections). He was quite disappointed that I found his stash -- I on the other hand was quite amused and happy.

@Rock Doc: Are you addressing this to me? I haven't actually bought these tiles yet - when I do, I will definitely be going for the handmade ones. They're a work of art and irreplaceable in my opinion. However, there are also screen-printed tiles available in the market in more or less the same patterns; the workmanship is of course different, but you get them cheaper, and they're also more easily available. You could give that a shot. I'd recommend Aakaar Flooring Solutions - they're here on Houzz and are able to provide both the above-mentioned types.