strategies for mechanical bosses

[catnip]

I want to know the easiest way to kill them, the type of arena, set, etc...

(just dodge is not the answer)

[kbm demon.♡]

Arena:
Campfire, Heart Lantern, Bast Statue, Sunflowers, Heart Statues

Titanium > Adamantite

Destroyer: Daedalus Stormbow w/ jester arrows for range or Meteor staff for mage.

Twins: Megashark or Onyx blaster with crystal/ichor/cursed bullets for range or Crystal storm for mage

Skeletron Prime: Megashark, Onyx blaster, Crystal storm or Meteor staff
For melee just go yoyo.

Tip: If you're playing Master Mode, don't go for warding unless you're playing melee. Go for movement speed or damage/crit if ranger/mage
Also here you go class setups.
https://terraria.fandom.com/wiki/Guide:Class_setups

[kbm demon.♡]

Or just blow em up with fireworks what do I know.

[Mosterd]

my twin arena is the intire sky (gravitation potion)
works for prime as well

[TaterTot]

Use fire to kill :) Another good tip is dont die :) Dont forget to jump too :P