Solid color, neutral pillows on a brown couch..
Decorating Secrets - Interior Design Secrets
Casa Cortes Vintage Metal Keys 2-Piece Wall Art Decor Set | Overstock.com
A different way of displaying photos. Would be easier to add to than hanging individuals -- Did this as a part of my photo arrangement on the wall going up the stairs. I used a bunch of different wooden frames in different sizes then for each ledge I got one silver frame that was really different to add a little pop.
Hidden doors -- This company makes cabinets, bookshelves and anything you can think of that fits your existing doorjambs thus hiding the door (and also making use of the space). If you click through checkout the "gun cabinet" door. Lots of great ideas.