Have you ever tried using textures in your designs? They are a great way to add interest without adding motifs to a design. I like to use textures from www.cgtextures.com. They have tons of free textures for download as well as lots of tutorials.
Image 1 (before texture)
Image 1 (Before texture is applied)

Below is an example of how I applied texture to Image 1 (created in Photoshop).

I used two textures downloaded from CGTextures:
 1. The first is found in Marble:Other, and is MarbleOther0001 (Texture #3195) 
 2. The second is found in Fabric:PlainFabric, and is FabricPlain0027

(Texture: #3144).
 I downloaded the largest images in both instances.




Back in my Photoshop image....
Step 1 - Marble Texture:
I created a new layer and moved it to the top of the layers palette. I then pasted the Marble texture into the new layer and set it to "overlay" mode. I resized the texture to fit my image (I did not try to tile or repeat it). I created a “curves” adjustment layer and a “hue/saturation” adjustment layer, to take down the contrast and remove the color in the Marble texture. I clipped both of these adjustment layers to the Marble texture layer (so that the adjustment layers only apply to the Marble layer). 
Marble Texture
The left Image is the original downloaded texture from CGTextures. The right image is the result when the original image is modified with adjustment layers.
Step 2 - Fabric Texture
Next I created another layer, moved it to the top of the layers palette, and pasted in the fabric texture, setting the layer to “soft light” mode. I resized the texture to fit my image (I did not try to tile or repeat it). I created a “hue/saturation” adjustment layer to remove all the color. I did not need a curves adjustment layer for this texture because there was not a lot of contrast. I clipped the adjustment layer to the fabric texture layer.
Fabric Texture
The left Image is the original downloaded texture from CGTextures. The right image is the result when the original image is modified with adjustment layers.
Picture
Step 3 - Group the Textures
Finally, I created a new group and placed both the Marble layer and the Fabric layer in the group (along with their respective adjustment layers). I placed the group at the top of the layer palette (above my original Image 1 design layers). I set the new texture group to “pass through” mode.


Image 2 (after texture)
Image 2 (After texture is applied)

The result is Image 2.

As you can see, in this design, I found the best results by adjusting the layers to be desaturated and without too much contrast. I just played with the layer modes until I found the ones that worked.

Have fun with textures!

--Sarah