Rick, thanks so much, I knew I could count on you for the details!
Um, I don't think I have time to get organza bags. And honestly I have to make sure I am seeing seeds and not flowerbuds on some of this. They are quite tiny! (I do actually have some colored gift bags, come to think of it, but they're fairly small. Maybe I'll hunt them up and try them out....)
I think what I will probably do is attempt to keep the flowers as dry as possible, and then when it looks like seedheads are there, just let them dry on paper inside...... Maybe. First I have to check out all those links.