Artwork Should Complement Your General Theme - Consider your furniture before hanging your prints and paintings. While you want variety in your displays, you also need some cohesiveness. If your frames or artwork “fight” with the furniture in the room, guests may feel unsettled. Period-style furniture (ie. modern, Victorian) is best paired with matching artwork.
Use a Variety of Sizes - You can add visual perspective through the use of small and large art. A framed collection of art brought together through a common message such as frame color or subject can also be quite interesting visually.
Do Not Overdo - In most cases, a few well chosen pieces will have more impact to viewers than many.
Consider Texture and Form - Variety plays a role here, as well. Too much of the same type of art can detract from your home. Make sure you mix it up by including works of art of differing textures and mediums.
Love Every Piece - Despite the advice given above, the key element in displaying any art in your home is that YOU love it. If your chosen pieces reflect your values, attitude, and dreams, then your viewers will recognize the connection and enjoy your displays.