One of my Buyers was just talking with me recently about decor trends here in the San Antonio area.
Of course, we have a lot of beautiful model homes here and my Buyer had asked me to photograph one of the homes that we had seen in a community north of Blanco Road and Loop 1604: Canyon Ranch Estates.
The size of the wall decor (which may not necessarily be "art"), and associated accessories was of special interest as it is larger than many home buyers (and those interested in selling their homes), may be accustomed.
When you are assessing the scale of a piece or your accessories, you have to consider not only the size of the room and the height of the ceilings, but the effect that you want the piece(s) to have - in other words, how dramatic you wish them to be in the scope of the decor when set against the the furnishings and wall color. (Please note that when this home was photographed, the time of day as well as the light in this particular home made the wall colors appear much yellower than the "latte" shade that they are painted.)
In the following sequence of photos, you will notice that all of the framed wall decor is over-sized and that accessories are fewer in number, but larger that what you may have in your home. The frames themselves are darker and wider to be more dramatic.
Another important, and easily imitable concept is to have enough contrast against the wall color and furnishings for the decor element to "pop".
So, don't be afraid to go a little bigger and/or more dramatic in your selections. That will allow you to reduce the number of elements in your room, letting your carefully-chosen selections become focal points in the setting.