Melissa Mortensen. See her tutorial HERE. I decided to create my own lettering (or should I say numbering?). Hopefully I will be able to do a tutorial on making your own unique block letters and numbers...anyone can with the method my mom taught me. In the meantime, you can download the pattern and use it to applique to your heart's desire. You can click HERE for the pattern, or download it on my sidebar.
UPDATE: I changed the photo to show how the numbers look on the pockets. I am slowly getting all 36 sewn together.