This tutorial describes one way of creating an abstract tileable image by using gradients as the basis of the design. The tutorial was created for Gimp although I think should transfer to some other packages.
Part 2 which can be found here <[link]
> shows what happens to our final outcome when a change is made to a particular step in part 1.
If you do feel inspired to create a design then please post a link to it here as I would like to see the results you all come up with.