Just thought I’d share this tip for saving cilantro seeds, which can be used as a spice if they’re ground (that makes it coriander), or can just be saved for growing more plants.
Once the plants have dried out pretty well, use a pair of shears to cut the bottom half of the plant off. Bunch up the remaining top half, and tie the base with some twine or a rubber band. Hang that bunch upside down, then tie a paper bag to sit under it. Leave the whole thing hanging until all the seeds drop from the dried plant. It should look something like the picture above.