In Underfoot the visible armor is fairly straightforward. Each group named, in addition to its normal drops, has a chance to drop a piece of "clay". Each tier has a specific name, Stellite for tier 6, Celestrium for tier 7, Vitallium for tier 8, and Damascite for tier 9. Additionally the clay has a type which determines which slot it is for, such as Tarsal for Feet or Brachial for Arms (the slot is also listed on the item itself so there is no need to try and memorize the slot names). Each named has a specific slot it drops most commonly but there is a smaller chance for any other slot.

Once you obtain a clay you will next need to obtain a "template" which matches your class and the specific slot you are making. For example a Warrior making some arms would need a Vanadium Plate Vambrace Template and a Monk making hands would need an Immaculate Leather Gloves Template. These templates are player made using tradeskills (trivials well over 300) and tradable. If you are interested in making these yourself I recommend EQ Traders.

When you have the clay and the matching template, head to Brell's Rest up near The Gatekeeper. You will find the "Useful Automated Vendor" which sells "XYZ Bonding Agent". Each Agent has 2 classes listed, such as Warriors and Rogues on Martialism Bonding Agent, for about 1050pp each. Buy the Agent which matches your class and then combine the Clay, Template, and Agent in a Kiln (one is available beside the "Useful Automated Vendor") to create your armor.

Shadowknights, Shaman, Necros, and Beastlords may then combine their wrist armor inside a Box of Latent Energies (also sold by the "Useful Automated Vendor") to change the focus on it.

If I get time I will break down drops by common source.

Visible armor from raids follows the same rules as from group. Palladium from Tier 6, Iridium from Tier 7, and Rhodium from Tier 8. Combine the clay with the appropriate template and Bonding Agent in a Kiln to create your armor.