Sometime last year, I don't remember when or where, I came across a site called Texture King. This site offers totally free stock images of textures of all kinds. You don't have to be a member of anything, you don't have to sign in, all you have to do is go there, select the textures you like, and download the ZIP files. The site says:
The stock photographs on this site are free for use in any situation by anyone with only one exception. DO NOT sell, redistribute, or host any of the stock photos that are found on this site.The above image was created using 8 different textures with a combination of blend modes, one mask, and a hue/saturation adjustment layer to remove some green that threw things off. I also feathered a duplicate layer in Multiply mode to add a little bit of a vignette.