As well as finding much enthusiasm for fruit and vegetable gardening, I have begun seed-saving. Don't know where that came from except maybe a deep desire to recycle!
So far I have saved dill seeds, mustard leaf seeds, sage seeds, Russian Black tomato seeds (and some "Granny's Bonnet" (aquilegia) seeds - not a veggie, but very pretty with easy-to-spot seed pods). I dunno if its a response to the 'GFC' (Global Financial Crisis) but there are a lotta people going back to growing their own food. I now have very healthy Russian Black tomato plants from a neighbour's tomatoes from last year - my first seed-saved babies!
I never took much notice of seed pods of plants before. Now they look like gold to me. Next to water and healthy soil, they are the most precious 'commodity' we have.

Above: Russian Black tomatoes (green :))
Below: Mustard seed pods & Dill seed 'umbrels'

Some advantages of saving seeds are that you know the life of the seed's parent and what has been put on the soil (or not - eg. no yukky chemicals or sprays) and by growing well, it may have adapted to its local microclimate and have offspring happy to grow in the same area. And of course it gives you propagation power!
I have been using a book called "
The Seedsavers' Handbook", but I have also joined a local seedsaving group to swap seeds and tips.
You can't let everything go to seed at once. For example nearly all brassicas (mustard, bok choi, cabbage, cauliflower, broccoli, brussels sprouts, etc) will cross with each other, so the offspring may not be what you expect!
All-in-all very satisfying and an exercise in patience as seed pods may take months to grow and dry on the plant.