In both older and current cultures we see stories, songs, poetry, and a variety of knowledge passed down orally. Some of these, like Homer, were eventually written out and passed down using the written word. Texts, once extant, were generally passed around by copying out or mass printing, but generally were not memorized and passed along via orality or memory techniques. Obviously there are examples of people memorizing large portions of text personally, but this has generally not been the major mode of passing knowledge from one generation to the next.
Dr. Lynne Kelly’s text book Knowledge and Power in Prehistoric Societies: Orality, Memory and the Transmission of Culture (Cambridge University Press, 2015) does a solid job of covering some of the techniques in the archaeological and even contemporary records on this score.
We have modern anthropologists attesting the oral methods you describe from several peoples around the world. Kelly’s book, based on her Ph.D. thesis, does a good job of summarizing many of these. She and Dr. Margo Neale also recently published Songlines: The Power and Promise (Thames & Hudson, 2020) which covers current Australian Aboriginal tribes which use these oral techniques for knowledge transmission as well. The techniques do vary from culture to culture, but on the whole they tend to share many features.
As others have mentioned, Walter Ong’s work, and the book Orality and Literacy (Routledge, 1982) in particular, will provide some additional context.
On your question of practicality, I’d recommend Kelly’s book Memory Craft which currently outlines the broadest number of mnemotechniques out there and provides some advice about which methods are best/better for particular applications. Following this, if necessary, you might focus in on the methods you’re interested in most and hone in on other texts, audiobooks, or posts here in the forum.
Everyone’s abilities and needs are slightly different, so experiment a bit to see what appeals to and/or works best for you.