Well there is not a certain defined way to make tribal textures, you will need to practice using GIMP.
But a useful tip that may help : go to
Deviant art and search for tribal brushes, then follow the steps given to saving them into your GIMP directory.
This may help as there a re thousands of custom brushes there. Have a look around and take your pick.
Although for the more skilled users I highly suggest using the paths tool in GIMP to create your own.
Last edited by Velve; Aug 3, 2008 at 06:30 PM.