The absolutely simplest way to make a "good room" is to opt for deep windows: the deeper the better. It creates a window as a "place" instead of a mere "opening" and it works in absolutely all types of residential buildings/homes, and all rooms in them. 
If your walls are simply not thick enough to create the necessary depth, the only option is to "build up" the edges and surrounds with woodwork. It also works well, but is tricky because less than optimal work will inevitably look tacky. Here it is done rather well:
The exact same thing goes for the outside of a home: all windows ought to have window surrounds that match the rest of the building, if a stately home. For a low key humble home, always go for shutters. Nothing else will deliver as much "sense of home" bang for as few bucks.
Look at what happens to a humble window on a humble home if we leave out the shutters: it immediately looks less inhabited, like a potting shed or mud room or basement entrance. This look has its place for sure, but not on the front of the main home of a family.
If you want more "depth" but don't have the wall thickness, building protruding bay windows is perfectly acceptable. The windows can be relatively unadorned to full length with extra floorspace and on corners they can grow to become proper turreted towers. Anything except flush!
