I think Kevin leaves them until nice and dry, carefully cuts the stalk and places it in a paper bag. You can even write the name of the plant on the bag, and whatever other information you want to remember. They will keep in the bag until ready to plant.
If you look at a dry seed head they are usually facing upwards.
This photo is looking from above, down into the top of the dry bloom cluster. This one is not dry enough yet.
