it's basically simulating the stitches without thread. it can be done with a template (SU! sells the template and tools in the crafter's toolkit) and a paper piercer. the template is a plastic square that has small holes all lined up and evenly spaced from each other - there are two different spacings so you can have your holes closer together or not.
basically, then you line the template up on your paper with a small hard mat underneath (also available in the toolkit), and use the paper piercer to poke holes through the holes in your template and through the paper.
when you are done, you have an affect of sewing, just without the thread. I suppose you could then (if you really wanted), use a needle (also in the toolkit) and thread and stitch through your holes.
hope that helps!
lori