I am just learning to use photoshop and must say it has intimidated me for a long time. Many probably already know how to do this but it is my first effort. I found the tutorial from Gillian Allen on the art-e-zine website. It is too lengthy to post here but if you go to her website or the art-e-zine website you can pull up the instructions. This is a way to make any image into a stamp you save on your computer. Then they can be printed out on fabric or paper.
The one I posted here was made from a photo I took of dried poppy heads in my garden. Im still refining the technique.