Crafting Quartz, Prismarine, and Lapis Armor
These three sets use materials from the Nether, the ocean, and caves respectively. Pick the one that matches where you are already spending time.
Quartz Armor
Mine Nether quartz ore in the Nether and craft Quartz Helmet, Quartz Chestplate, Quartz Leggings, and Quartz Boots using the standard shaped recipes. Quartz is plentiful once you are in the Nether, so this set is easy to mass-produce.
Prismarine Armor
Collect prismarine from ocean monuments or by crafting it from prismarine shards. Use it in the same four armor shapes to make Prismarine Helmet, Prismarine Chestplate, Prismarine Leggings, and Prismarine Boots.
Lapis Armor
Mine lapis lazuli ore and craft Lapis Helmet, Lapis Chestplate, Lapis Leggings, and Lapis Boots. Lapis is common at mid depths, making this a low-effort set.
Choosing Between Them
All three use identical shaped layouts, so the only real decision is material availability. If you are already mining lapis for enchanting, Lapis armor costs you almost nothing extra.