In the past month or so I let quite a few of my herbs flower and then go to seed. Collecting seeds is a pretty easy (and free!) way to get more plants.
In the photo above I have some dilll and cilantro seeds, and the templates I photocopied from You Grow Girl by Gayla Trail. I am planning on using the orange and brown polka dot paper to make the seed packets.
Saving seeds is pretty easy. When the seed heads were fully formed but still green, I cut them from the plant. I then put them in a small plastic cup and let them air dry. When they were completely dry (it took about 10 days) I removed the stems and was left with what you see in the photo.
Making the seed packets is just as easy. You just trace the template on to the paper, cut, paste, and voila! You can make pretty packets out of patterned paper (check the scrapbooking section of your craft store; even Target has some neat scrapbooking papers) and then host a seed swapping party as Vanessa Richins suggests (anyone in So Cal want to meet at a Coffee Bean and Tea Leaf and swap seeds with me?).