Here’s a cursory demo “Using Images to Create Patterns” that is the same for both Photoshop CS4 and Photoshop Elements 8.
I will briefly explain this process with an image from the KathyAnne Art site - The image title is Journalpage_leaves and it is on page 9 of the Journaling Section. These instructions are the same for both Photoshop and Elements. The only difference is the menus are slightly different in both programs. Since it is great to learn something and remember it, I am only going to tell you what to do and let you find out where it all is.
Open your image.
Then make a selection using the marquee tool (set the tool on fixed size with a height and width of your choosing. I use 4” x 4” on this sample)
Open a new file (command n mac) (control n pc)
the same ppi as your original image and twice the width and height as the original selection. (My new file is 8” x 8” with 240ppi)
Copy and paste the selection to the new image file.
Now make another copy by either (command j mac) or (control j pc)
Move both the selections to the top of the box to where the edges meet.
With one of the layers selected, flip the section horizontally.
Next merge the 2 layers till they are one and copy that layer by (command j mac)
or (control j pc) and move that layer to the bottom.
Flip the bottom or top layer vertically and merge them again.