So, I would consider Lord of the Rings to be high fantasy. I'm going to say Harry Potter is low fantasy. These are my baselines.
Size restrictions seems like a strange place to start on your part, but I can see where you're coming from, in an Attack on Titan world, a normal life would be fairly difficult. I will come back to size in a minute.
Sharkn8do's guide to the "normal"
As pop culture has told us for the past two decades, normal is a fantasy... I would presume a low fantasy, but a fantasy nonetheless. I'm going to assume what you mean by a normal life is the ability to have a chosen profession: farmer, shopkeeper, guard, etc, without needing to interact with the insane fantasy that the protagonist will in movies and video games. This is done in a number of ways, so let's look at them all.
There are a couple classic tropes in movies and video games that explain how the dragonborne can shout skeletons across rooms, but people are disabled by taking arrows to knees. Because tropes require specific examples, I'll be pulling from everything, and will be looking at all fantasy, not just high.
I lump these together because at the heart, they are all the same trope. One person or group of people is special. Whether this is because of their bloodline, their race, or they were chosen by a deity or higher being. This is your skyrims, your harry potter, or basically every superhero movie ever, where others can't do what you do because you are special, and that's the way it is.
Sometimes, it's not because you're different, it's just because you're smarter, or have put in more time, or whatever it is. You trained real hard to do what you're doing, and others didn't. Anyone could do what you can, they just don't put in the time to do it. This would be like metroid, or assassin's creed.
Maybe they aren't aware of what's going, and don't care to. You saved the world and did all the magic, but no one really knew what happened. They know what the world might hold in the realm of magic, but you've seen it. This would be your lord of the rings, your supernatural, that kind of stuff.
Combination of any of these
Maybe they're oblivious and didn't get the education, maybe you're special and needed to be trained (Jedi), but for whatever reason, they don't interact with fantasy worlds in the way you do, and that's okay.
There are a couple ways you can build your world so that you don't necessarily have to play into any of these tropes, but can still explain why donkey is having making drankey babies with a dragon, and you're making gingerbread.
The grass is always more magic on the other side of the fence. All the good stuff happens over there, and Joe the mechanic is okay with that. Bilbo had to walk this way to find the magic happenings, while the shire was okay with doing their thang. You can do this fairly easy in a world without mass transportation methods. Just make it so all the good stuff happens over there, and all the normal stuff happens over here.
For some unexplained reason, the towns in skyrim, shovel knight, and all that good stuff tend to be unharmed, while right outside bad things happen almost constantly. Whether it be a big old wall, or just dragons don't like towns, you can do this fairly easily.
Disregard Fantasy, Acquire Currency
Sometimes a group of people just refuse to do anything about the magic, or the war, or whatever. They set up shop in the middle of a wasteland, and don't care about what's going outside of their world. The fantasy might blow through every now and then, but then they go back to their thing. They have a farm to plow, so they're gonna do that till they die.
Now, there are things in your world you can't have if you want to maintain the plebeian population. You touched on size, you can't necessarily sit in your shop and sell discount produce is you're 3 feet tall, and you have 50 foot behemoths regularly stomping all over your discount produce. That is one example, there are a couple others I can think of.
If everyone's super, then nobody will be. If we all do the magics, and there's a constant threat of dying or world destruction, you're probably not going to feel the need to put in that 9-5.
You will need a central economy to motivate commoners to do the commoner thing. If people can pull all their needed things out their magic pouches, why would anyone do anything? You need that realism of "hey, I want to eat, where do I get that food from?"
The best example I can think of is Avatar. Nobody did anything lame in Avatar. Everyone was awesome, and all they did was braid each others tails and fly on things. You can't have that, joe is now sailing birds and eating fruit out of the air, he's not going to be writing you a paper check for a mortgage.
This one is going to seem weird, and that's because it is. But, you know, we exist in the third dimension, so somethings have to exist in the 2nd or 4th dimensions. You can't really have that daily grind when you're an nth dimensional being who is everything always.
This one can be overlooked as well, because we are such creatures of habit. But, if your world is constantly getting blown up by vogons, or you have monsters coming out your closet on the reg, chances are you're not going to be doing anyone's taxes anytime soon. You'll probably be dead, or looking for gay monsters.
So, unfortunately, as awesome as it would be to have your universe be an acid trip on the fourth dimension, you need to have a decent amount of realism. If you want a crazy world, add some realism, does it make sense that dragon's attack very few towns? no. but Bethesda decided to allow the poor people of white run not die every two days. Hopefully this helps.