I think most people understand the concept of balancing a room - you don't put all the heavy, dark furniture on one side, you don't want white walls and ceiling with dark floors and furniture, you don't paint an accent wall dark without balancing the color with accessories in the rest of the room. One thing that I often see overlooked is the idea of balancing a room vertically. You can tell when a room isn't balanced vertically because everything will feel very low to the ground, and the room will feel very short. You want to make sure that whatever colors you choose go all the way up to the ceiling, and I am not just talking about the wall color. Here are a few ideas for making sure that your room is balanced vertically.
Simple curtains are an effective, affordable way to draw the eye to the height of the room. Hang them as high as you can, while still having them sweep the floor or the window sill. If your walls are light, but your furniture is dark, consider using a curtain that will contrast with the wall color and bring some of that darkness up. The curtains don't need to be the same color as the furniture, but they should echo it. The same goes for if you have a dark wall color, it is helpful to break it up with a lighter curtain for contrast and vertical line.
Curtains are not the only way to bring vertical lines to your room. You can also balance with pictures or shelves on your wall. If you have a bold rug, you will need to echo some of the boldness in the wall art.
Furniture is an obvious way to bring vertical lines. You don't want all your furniture to be three and a half feet tall. This is why china cabinets always look amazing in dining rooms. It brings the eye up. For your bedroom, look for pieces that have some height, since bedroom furniture tends to be very low.
Lamps are one of my favorite ways to add height. But again, consider your color scheme. Do you need a lamp that is eye catching because all your other eye catching elements are on the floor? Or if you have chosen a bold wall color, you might need a generic lamp to balance out generic furniture.
I find it helpful when decorating, to do a quick sketch of each wall and shade the items that are bolder. You will immediately see where your holes are and if you need to fill in with a light or dark tone.