Take my advice with several grains of salt, but I think there's some ways to help:
1) Only explain what you need to, what's over the next hill may be a complete unknown. Remember that a lot of these tales were told by people that didn't often travel far from their home village.
2) Related to the above, it may be useful to avoid thinking of all supernatural feats, objects, and beings as coming from one source. For instance, the knight's magic amulet being powered by a different force then the wizard's spell (even thinking of them as "powered by a force" feels too modern, but the example still works I hope).
3) Strike a balance between fantastical things not being everyday, but normal people still taking their presence for granted. A peasant might not see a fairy every other week, but when he does he doesn't treat it as a once in a generation experience.
Other than that, maybe do some reading on the mindset of people in the medieval period. I'm not nearly an expert on that, but what little I do know is some pretty interesting stuff. If I'm not mistaken, people back then saw even real life events as an allegory for deeper spiritual truths, for example.
You say I am loved, when I don’t feel a thing. You say I am strong, when I think I am weak. You say I am held, when I am falling short.
Number one there is definitely important. The idea of a "Just So" Story is a good reference for that I think. Generally that's more mythological, but I think there's overlap. Those sorts of stories would often have strange things happen and just be sort of be taken for granted, partially for the symbolic meaning of them. The story itself might be explaining something, but what happens in the story can often feel pretty arbitrary.
I don't know if I'm explaining it well, but sometimes you'd also have events that are kinda normal, but are done at an unusually large scale or are more literal than you'd expect, but again they're sort of treated as if it makes perfect normal sense (not like a superpower).
It's not a classic example, but a more modern story that I feel does it well is Dark Souls. For instance, Quelaag's Sister took pity on the infected followers of the Chaos Witches and sucked the blight pus out of them. Kinda like using Suck Out the Poison in a "Just So" Story, because sucking the pus out itself sounds possible (if unhelpful), but having someone who looks normal (at least from the waist up >_>) being able to do that on a mass scale without any particular justification, just to explain part of the setting, is part of what makes it feel more classical, I think.
Another thing that turns up in a lot of older stories, is... well, I can't think of a good way to describe it right now. Recurring number themes? Something like a repeated number of brothers, or treasures. Or sometimes more importantly, a theme with a specific time frame. Like you must return an object after seven days, or someone vows to return in exactly seven years (and whether or not they can fulfill that being connected to some meaningful contract or curse).
Food Chains and concepts like that are also common themes.
I think Spirited Away captured what I believe you're thinking of in a modern story, so it might be a good reference.
Edited by Jokubas on Dec 27th 2018 at 1:34:43 AM
This isn't really for a specific project I have in mind, but could be useful in a number of future endeavors. Basically I was thinking about the Fairy Tale Free-for-All trope, and how its purpose is to bring together stories from our childhoods, along with doing something new with them such as Grimmification.
But it occurred to me that FTFFA shows and works, such as Once Upon a Time, usually don't really rely on the actual stories from our childhoods, but basic stories. What I mean is, you can put the Gingerbread Man in your story, and I will recognize who that character is, but I won't necessarily feel a connection and familiarity with the character unless it feels, to me, like the Gingerbread Man I used to read about with my mom when I was a little kid.
So what I'm wondering is, does anyone have any ideas or thoughts about creating a work using fairy tales that has a strong chance of actually evoking the experiences of those tales in the audience's childhood? I get that this is a tough one, but I'm interested to see what you guys have to say about it, and if you come up with anything.