Generic Gears

Below are noteworthy custom gears applicable to ALL classes in heRO that should be helpful for almost all classes in their default builds. Note that God Items and MVP Cards are excluded from the list.

Aumdura's Grace is a great generic accessory with a slot and all stats, suitable for almost any build Boitata Armor is lightweight with a little bit of relevant stats for every build, great for making generic armor that's needed by every class such as slotting in Marc cards
Green Apple Ring is easy to obtain from a mid-tier mob yet is generically useful, especially before you have any cards
Lantern of Hope has great benefits but is only useful if you are affected by status, or you have a way to inflict it upon yourself
Tidung has niche use cases for assembling 100% status resist gears without having 100 vit
Ancient Gold Ornament is a good headgear that provides well-rounded stats, at the cost of requiring a high base level and difficult to obtain from the Biolabs
Anarch's Reign and Order have no stats but they are decent substitute when headgear cards matter more than any headgear themselves. They can be used when slotted mid headgear are unavailable

Wings

Zodiac Stone (Zodiac Wings) is helpful for its Double Wing Effect allowing you to take advantage of powerful headgear or armor cards. This can be upgraded to Light/Dark Allegiance Gear wings which are stronger than the Zodiac Stone (Zodiac Wings) but harder to find and more restrictive as it requires allegiance.
Flower Wings has niche use as it's easily the highest default raw DEF and MDEF even at safe refine due to the Double Wing Effect
Aerial Wings, Arctic Wings, Gaia Wings and Phoenix Wings are cheap access to elemental armor without hunting for its cards, while being a decent defense rating for every class when elemental armor is needed

Draconic Power Set

Set of Gears from Abyss 4 Instance Dungeon
Dragon's Rage- generic garment belonging to the Draconic Power equipment set
Dragon Scale Boots- generic footwear belonging to the Draconic Power equipment set
Silver Dragon Orb- generic accessory belonging to the Draconic Power equipment set, though primarily for healing or for the holy armor enchantment
Purple Dragon Armor- generic armor belonging to the Draconic Power equipment set, though primarily for melee combat
Bone Dragon Mail- generic armor belonging to the Draconic Power equipment set, primarily for tanks on the front line
Black Dragon Robe- generic armor belonging to the Draconic Power equipment set, primarily for magic casters
Purple Ferus Card- unique card that fits in every slot to empower the Draconic Power set
Silver Acidus Card- unique card that fits in every slot to empower the Draconic Power set
Black Acidus Card- unique card that fits in every slot to empower the Draconic Power set

Elemental Set

Based on Elemental Ring, power is granted based on the element of your weapon. Its bonuses can be applicable even for non-combatants as long as the element of the weapon match. This is a soft-combo and you do not need all pieces except for the Elemental Ring, so pick what you need for your build and element of your weapon.

Elemental Ring has no bonus on its own but powers up the entire combo
Elemental Robe has decent MDEF and give certain elemental resistance and status resistance Elemental Cape can be used to do specific bonus physical damage to the 4 basic elements

Useful Support Gears

Magic Lantern is useful if you need emergency Sight without using Horong card
Smoke Emitter is a great all-purpose gear for activating Perfect Hide.