Do you have a specific seed in mind? Try the search function at the bottom of the ws front page. Ask about specific seeds and someone will share their experiences. There is also a Seed Saving forum that you can explore.

Most seeds will be ready when their pods or blossoms are brown and crisp.
Some are easy to collect, poppies, dianthus, malva, and balloon flower can be held over a bag or envelope then squeezed to release the seeds.

Rudbeckia and echinacea seeds are difficult to find until you have had some practice. Both hold their seeds amongst the blossoms. When the blossom is dried on the plant they can be picked. The rudbeckia seeds are tiny dark rods. After awhile you will recognize the seeds. For me it was "aha, there they are" moment.

I take various sized envelopes out to the garden to put the pods or blooms in then take them inside to find the seeds. For large seeds, blossoms, or large amounts of those I use a paper lunch bag. If they are not already very dry I leave them in the bag/envelope for a few days to continue to dry. Others spread the seed pods onto a paper plate to dry.

Later I open the pods and collect the seeds while watching (actually listening to) the TV. The collected seeds are then put in a 2 1/4 x 3 1/2 paper coin envelope. When I am ready to trade I use either the paper coin envelope or very small plastic bead bags. I use cut down boxes with strips of cardboard cut for dividers to store my seed coin envelopes alphabetically. There are boxes for perennials, annuals, veggies, etc.

Sometimes I find myself without an envelope/bagand just stuff the seeds into a pocket. LOL, that's why I have so many mystery seeds.

Others have different ways.

Have fun!

Here is a link that might be useful: Saving seed

I have been harvesting for several months now. It depends on what plant you are talking about. I harvest them and then dry them and bag them up for giveaway.

What are you considering harvesting?

Also, consider the Seed Saving Forum.

I am looking at harvesting marigold seeds mostly.

How easy is it to harvest coneflower, daisy, blanket flower, alyssum and coleus?

Marigolds will dry and you can peel off the papery pod and harvest the sticks. Define coneflower. Echinacea, ratibida, rudbeckia?

Gaillardia forms prickly heads and the seeds are ready when you can use your thumb and flake them off. A gaillardia seed is viable when there is a hard "egg" at the base of each of the ballcocks.

Make that shuttlecocks and not ballcocks. Getting badminton (sp?) confused with plumbing.

My strategy has been to peel, smush, and rinse any "fruit-like" shrub seeds and keep the seeds moist. For herbacious plants, I've been waiting til the "pods" appear dry and the seeds are naturally spilling out or about to pop out. Sometimes this means I've missed them or insect pests may be present. I'm sure looking up each species might produce better results, but I probably have more seeds than space to grow at this point anyway. I've been drying them and storing them in envelopes til time to plant.

Coleus is easy, the flower spike eventually gets dry and you can break it off and put in a bag or an envy. The seeds will fall right out.