Seed saving is a great way to grow more plants for yourself and sharing. And just swapping seeds is the easiest way spread different varieties amongst your friends. I have done this with many friends I have met in gardening groups online too. The most important things are to keep an eye on the developing seed pod and don’t cut them too early. One option is to put a mesh bag / organsa bag over the developing pod to catch the seeds when the pod opens. To know when the seeds are ripe it helps to sample and look at the seeds. Mature seeds will usually be dark and hard. They come in all different shapes, but they should be recognizable by their distinct uniform shape.
All the pods on a bloom spike will not mature at once. If you are not careful you will knock loose many seeds as you try to collect the first, you see. So, I often carefully cut the whole stalk while holding it upright so as not to dump the seeds. I put the stalks in a container to catch any seeds that fall out right away. I have found that by cutting the whole stalks that are still green that more seeds will mature if they are stored in shelter and allowed to dry slowly. Always store these stalks or any newly collected seeds in an open container or a paper bag. I will leave these Henderson checkermallow stalks several weeks to dry and allow more seeds to mature. Then I will crumble that all up and go through a process to get clean seeds (that will be another article)
To prepare for growing seeds do a little research for each species. Some I plant in November so they go through a cold, moist period that is necessary before they will grout / germinate. Lupines and checkermallow germinate better if they are scarified, had their seed coats scratched by rubbing with sandpaper. Columbines and other small seeds should be sowed on the surface of the media, so they get light needed to stimulate germination. Also sow most of your seeds in a good soilless media to reduce loss to rotting and having weeds smother the desired seedlings. The exception would be some large seeds that produce robust seedlings that will tolerate some extra seedlings in the pot. Look for more articles or events to learn more on cleaning seeds and growing seedlings.