Many times a room only has the phase "I like" in common. Meaning that the room is filled with objects, furniture, and wall decor that the only thing they have in common is that the person who picked them out likes them. To help solve this problem and to make a more coherent room, start with a focus point and work around it.
This focus point can be a painting, a sculpture or any other object that has a style and a color scheme. Often people do the same thing with picking out their clothes. For example one might start with a blouse they like then pick out pants, jewelry and shoes that go with it. See the image below for an example of this.
Well a room is the same way. Start with a focal point then pick out furniture, accessories, paint, etc. that matches the focal point. The final result is a well decorated room that has object that have things more in common with one another than just "I like it."