Strongholds are a bit.... well bland. They can be improved and must be since there a vital structure in the game For a all important structure the only thing I found interestingly enough are the Libraries and the portal rooms.
Strongholds are ment only for the ender portal. Even then, two rooms aren't good enough?
Well before I propose new Stronghold rooms other than the library,portal room,jail cells and fountains, I want to return the strongholds to the surface. No, not all three of them! maybe one or two but never three. They would look like the original version of strongholds.
Only one, otherwise this would make strongholds way easier to find.
Now into the idea to the different rooms a stronghold should have. The first one is an entrance, an actual entrance rather an exposed entrance to a nearby cave. It would look like fountain rooms but with some sort of kiosk made from wool and wood blocks. (I have a photo for it but don't know how to upload it). It has a chest with paper or a book
I would like an entrance, but I don't want it to look like a store, nor made out of WOOL. It's abandoned fortified structure made out of sturdy stone, not WOOL.
Next a brewing room, a simple room with a cauldron and one or two brewing stands, a chest might be in here with nether wart or golden melon slices
Too over powered, it would make going to the nether less vital for the game and potions to easy to make.
Then a small forge similar to villages it has a small pool of lava and 2-4 furnaces a chest containing armor or weapons.
Not bad, but there are already a loooot of chests containing armor
Lastly some sort of "graveyard" in a small room made out of smooth stone with dirt as covering, under them are chests filled with rotten flesh and bones.
As for the stronghold entrance made out of wool (only the kiosk), the desert temples seem to be made out of it, and they're ancient.
As for the brewing room. You probably had about 2 stacks of blaze rods before finding the stronghold, (for ender eyes) and the possibility of these room is low also, and the amount loot in the brewing room is low also like 1-2 nether wart or just one glistening melon.
Finally for the surface strongholds. Well maybe one stronghold maybe in the surface.
As for the brewing room. You probably had about 2 stacks of blaze rods before finding the stronghold, (for ender eyes) and the possibility of these room is low also, and the amount loot in the brewing room is low also like 1-2 nether wart or just one glistening melon.
Finally for the surface strongholds. Well maybe one stronghold maybe in the surface.