i think three things about villages should be improved 1) the aesthetics or looks 2) the loot that can be gained 3) villagers trades.
So personally I think villages are cool things to find if you're starting a new survival world, but after a while, they basically become useless. A lot of times too, after the blacksmith is raided, or if there is none, it's useless because the villagers trades aren't very useful, as a lot of this stuff is easier to get by hand instead of buying it. So here is my way I think villages could be improved
BTW, I know this is very long so I won't blame you if you don't read the whole thing
1) Villager trades.
I think trades could be improved in three ways: lower the prices on cheaper goods, allow villagers to sell better items(for higher prices of course), and make it easier to obtain emeralds.
As you know emeralds are kind of hard to find in survival, and it's not easy to buy them from villagers. If you go mining for them, by the time you've found them you don't need to buy any of the things the villagers are selling. I think the villagers should have lower prices for their emeralds (for example:5 wheat=1 emerald) Also i think the price on cheaper goods like wool from the sheperd should be lowered, or the amount you get increased(for example:1 emerald for 10 wool, or 5 emeralds for 64 wool)
The main reason I think villagers should be allowed to trade better items is because that way the keep their value for most of the game, instead of losing value after a certain point. They would be allowed to sell things like a diamond sword or armor, or level 3 enchanted books, however these would be at a higher price so that it isn't too op.
The third thing I think could be done to allow villagers more usefullness is to add a few more types. Some I was thinking of would be a potion brewer (so that you don't have to make all your own potions), a baker which would sell cake, bread and cookies(so that you don't have to get so many ingredients for making them), a herbalist who sells netherwarts, mushrooms, or other types of flowers, and a tanner that can sell you saddles and horse armor.
2) Village loot
As you know, the only place in the village which has good loot is the blacksmith(unless your into farming), and unfortunately some villages don't even have one. I think villages could have better loot simply by adding some chest with thing in it, kind of the ways adventure maps sometimes have. Also the loot in the chest can differ depending on which type of house your visiting, for example a butcher's chest could have some raw pork in it, but the librarian's would have some books, and maybe even some enchanted books. Just something simple like this could improve the whole finding a village thing as you would be able to get some good loot from finding one.
Common loot found in chests would include:
string, leather, iron ingots(not as common), emerals(rare), seeds, random pieces of leather armor, xp bootles, and random stone/wooden tools or swords(not as common).
You've got to admit, villages are not the most beautiful thing you've seen. However I'm not proposing that we get grian to go and create new village buildings or something like that, I thought of few things that could improve the overall looks of a village, while not turning it into the equivalent of a small build project.
There should be more height difference in the building/village. this could simply be done be adding two story houses and tall trees like the ones that naturally generate. There should be better build techniques used in them, simple things like a roof overhang, a frame, some window ledges, etc., nothing too complicated, just enough to make it look better. Some other things that i think could be cool would be some small aesthetic designs, like maybe some crates or chests lying around, signposts, maybe even gallows could be cool.
Some other things which I think should be implemented is more distinguished buildings. You know the way the blacksmith is easily recognizable, well something like that that would help distinguish certain buildings, like the librarian and the butcher from the others. For example, if a potion brewer got implemented, a wizard-ish tower for him to live in. For a herbalist(if it got implemented) a shop with a garden out back or a small greenhouse, etc.
Two other things I think that would be cool if added to a village would be 1) a small castle, nothing complicated, just something simple with towers, a throne room, and a dungeon. However this castle would have a 33% chance of spwaning, if it meets the criteria of at least four buildings, meaning that just because you find a village you won't have a castle. 2) A market place. It would just be some tents in a part of a bigger village, that contain villagers that sell random objects that aren't sold by other villagers. 3) I also think it would be cool if a village had more that 7 buildings has a small wall.
My main thing with villagers is the trading. In endgame, I wish villagers sold every piece of diamond armor, and any diamond tool, but they don't. I think this should change so that buying diamond items will scramble the trade and change it to a different one, maybe just a different enchantment. There are times where I wish dirt and sandstone were in trades, because I don't like over-stripping the landscape for these materials, and would rather do some trading and farming to get them. Farmers could sell dirt and a new builder occupation would sell the sandstone and special stone variants.
When it comes to loot and aesthetics, the one thing I always did when making a village from scratch was give the blacksmith a freaking anvil. I get there is a kind of reason for not doing so, but seriously. Just make it almost always damaged and more often than not very damaged. If the other advanced utility blocks had a damage function, I'd suggest them too in the same fashion. For loot items, maybe a small nerf to the percentages of the blacksmith chest and make other chests possible, giving you more loot options, even if it might be a hoe or a few carrots or wheat; maybe paper, books or an ender pearl.