I have some rituals, they aren't strictly necessary but I feel like the world is "incomplete" unless I do them:
1: Get some form of summon weapon even on non-summoner characters early for nominally higher damage and protection.
2: Build arenas literally everywhere; one side of the Ocean, Underground for key farming, in the central Forest biome, a box in the sky for Blood Moon fishing, a bridge of opposite evil blocks so I don't have to world hop, in the Underground Jungle for Plantera, in the Underground Desert for key farming, in the Underground Ice for key farming, smoothing out the Dungeon entrance for Skeletron, floating bridge of Hallow for Empress and Queen Slime, I even make the Golem room in the Temple into a flat box once I get a better pickaxe. I don't necessarily do all of these in each playthrough, but I do build most of them.
3: Quarantine all evil chasms before Hardmode so I only have to actively deal with the "V" spread.
4: Before settling on a world, I turn off auto-save and kill the WoF with an endgame character to make sure said "V" spawns the Hallow and Crimruption on the preferred side of the world, then close the process without saving so the world is reset for a new character.
5: Get all available useful equipment at each stage of progression even if I don't actually need it. So I'll basically have a Golden Fishing Rod, Golden Bug Net, Endless Lava Bucket and so on before beating any boss.
6: Build fishing pools and settlements in most biomes for easy navigation and transport.
7: Place appropriate biome torches across the entirety of the surface for marginally better lighting and luck.
8: Immediately quarantine the Crimruption side of the "V" when Hardmode hits by jumping to a new throwaway world, killing WoF then breaking all the altars in this world to generate the Hardmode ores, then mining them to create a better pickaxe for segregating the "V" quicker in my main world without creating even more spread by breaking altars there, or waiting ages fishing for ores/bars.
9: Cleanse every last block of Crimruption in my world barring a single chasm (just so I still have access to it) once I get the Clentaminator. I could theoretically do the same for the Hallow but since it doesn't prevent NPCs living in it, illuminates caves and makes them look cool, and replaces less music, I don't mind it spreading.
10: Place torches inside the entirety of the Dungeon to illuminate it, and remove all the traps just before beating Plantera.
11: Place torches inside the entirety of the Jungle Temple to illuminate it, and remove all traps before fighting Golem.
All of these are obsessive and unreasonable and they make my playthroughs take a minimum of 100 hours to complete, but I feel compelled to do them. I know world-hopping (which is required for some of these steps) is considered cheating but I don't mind it too much, and it saves me a headache.
For example, this is my last world, pictured above. It's a mess.
