Unify any space by repeating elements of pattern or color. Variety in scale packs a punch.
Here, I've used Baroque: Machiavellian on the side walls and chaise lounge; its somber tones do not overpower. The accent wall is covered in the same pattern, but in Baroque: Hot. Notice that the chaise lounge's piping is in a complimentary color which helps unify the room.
If you aren't sure where to begin, look for a collection of related patterns, or one pattern that comes in multiple colorways and scale options. By keeping two elements the same or similar (color and pattern for example) and adding variety with the third element (changes in scale, in this example) you can easily create a look that has balance and dynamism.
