for tomatoes, red peppers and the large sweet onions we get starts from the greenhouse. for everything else i save seeds. beans, peas, squash, melons, onions, some ornamental flowers.
by far the most varieties i have are beans as i've given up counting how many varieties and selections i have. i'm always finding more and working on cross breeds of my own. this past winter i had to winnow down the collection as i had way too many that i was no longer going to be growing so they all went into the potential eating or worm food bins.
i don't have freezer space for storing anything so they are kept at room temperature and have to be regrown every so many years before they stop being viable. the best way i know to preserve them is to find others to grow them too. the more people who like them and grow them the more chances they have to survive. i'm glad to say that a few of my crosses have now gone overseas to a friend in Poland so they have a good chance of surviving. i am always working on more so those are the fun projects. this year i'm planning on growing 30-50 varieties. i have twice that many i have sitting here that i would like to grow but that's not all going to fit so i have to pick half and hope i can do the rest next year.
heirlooms or possible heirlooms for the beans, squash are mutts and heirlooms. onions are mixed too now. nothing hybrid other than the tomatoes. nothing GMO either that i know of.