With the runes...well, there are rune poems indicating the meaning of the runes. I think it's better to read those poems than to accept what an author tells you the meaning is. Because frankly, I'd rather have my own interpretation, than to hope someone else isn't completely making it up.
I don't know much about runes myself as I explained in the initial post, so ty for that! That makes a great deal of sense.
In the case of Tarot... I think it would help to be aware of the origins of symbology used in the various decks. In the Rider Waite, there's a strong connection with Golden Dawn/ Ceremonial Magic symbology. Therefore studying those topics may help you pick out the little details that add information.
Yeah, i agreed with you there. I'm not too fond of that deck myself, i went with one centralized around greek mythology myself bc it resonates well with me and the celtic decks I had found didn't, but i did find it fascinating to read the background and history of that deck.
Bright Blessings