I was going to make several worlds to try and get as many the following:
* No corruption on jungle, desert or snow.
* Just one patch of corruption tucked to the side easy to control, but not right by the ocean, with no more than 2 deep shafts but plenty of shadow orbs.
* A pyramid outside the desert in its own oasis.
* Dungeon very close to the edge of the map.
* Giant trees near the dungeon.
* At least one enchanted sword shrine, close to the surface, but not on the surface.
* A spot with two fallen logs close enough but not too close, to walk from one to another and try and get fairies to spawn.
* Enough flat surfaces with plenty of room for artificial biomes and for meteors to fall without breaking anything else.
* A few deep caves to get into the Caverns without having to dig too much.
* A spider cave near the Center of the map, but not completely on the center so I don't cut it in half with the main central shaft.
* Also mushrooms caves near the center.
* A sizable flat area in the jungle to get a jungle town and bambo farm built fast.
* A large Lizhard temple tucked to the side of the jungle so I can make a shaft there without cutting the jungle.
* A few islands close together under the Space layer so I can merge them together into a large floating island.
So I name the first world "First Try", hit the button and I get this baby over here:
View attachment First Try.png
Seed: 3.4.1.142052222
It's got everything I wanted, and the pyramid has the magic carpet to boot. The corruption is eating away at the stairs of the dungeon, but it can be easily repaired.
The shrine is unfortunately gone in Classic mode, but it's otherwise mostly the same, just with more giant trees on the right, and only one of them reaches the dungeon shaft. There's still a couple of enchanted swords, just without the shrine.
Needless to say, I didn't have to make a "Second Try" map. This one will do fine as a main map to try and build a neatly ordered world with all the NPCs and biomes.