I though this was a pretty neat technique. (Link courtesy of Judy Howle.)
http://www.designertoday.com/tabinde...opDefault.aspx. A scanner is used to scan a paper bag and some colored pencils.
If you don't have a scanner, here's a tutorial on creating rumpled paper:
http://www.creativemac.com/2003/06_j...mple030603.htm
At the end you would need to add a Hue/Saturation adjustment layer set to "colorize" and experiment with the controls to get the desired shade of brown (or whatever color you decided to use).
~Danny~