To Do #1: Make sure when hanging your artwork that the center point of the piece or grouping of pieces is eye level for the average person. It's not always possible but it is a good guideline to go by.
To Do #2: Art size should be related to wall size. You don't want a small piece for a large wall or a large piece for a small wall. Things need to be proportional.
Notice how in the photo the wall is more vertical than horizontal so they used a grouping of art pieces vertically to fill the space. A horizontal piece or grouping would not fill the height of the wall and make the space seem disproportional.
To Do #3: Check your colors. If you are wanting a room with calming qualities find artwork that has neutral tones and a serene picture. To add life to a room, use pieces that have bright colors and images. Typically an abstract does just the trick. Matting or framing the piece in a focal color of the room; for instance the color of a chair or window treatment really pulls all the elements of the room together.
To Do #4: Bigger is often better. One large painting keeps things simple and can also draw attention to a focal point of a room such as a fireplace or one large wall painted a specific color.
To Do #5: Art should fit furniture size. Generally speaking, art hanging over furniture should NOT be longer than the width of the furniture. Keep it to about 75% of the width of the furniture.
To Do #6: Hang your piece or pieces low. When hanging the artwork, the bottom of the frame or canvas (if the piece isn't framed) should sit within 4-8" of the top of the table. This is an especially good rule of thumb when hanging artwork in a children's room. You want to make the art eye level to the kids.
To Do #7: If your room is small and not very opened up, add a landscape to the area. It gives the impression of having a window which opens up the space. Horizontal lines also add width to a room and vertical lines add height. Just make sure not to use both horizontal lines and vertical lines in a room. You end up cluttering up the walls and making the room look just as small as BEFORE you hung anything!
To Do #8: Hang securely. Attach the pieces securely with picture hooks rated for the weight of the object. Keep in mind you want to make sure the artwork butts up snugly against the wall. If in doubt, ask the advice of your local hardware store.
Remember these easy tips when hanging your next art piece and your room should look amazing!