A list of costumes in Blade and Soul you can farm solo.
Wheel of Fate Costumes
Most of the Wheel of Fates you encounter while leveling will have an outfit/adornment in addition to the weapons. The Cinderlands/Viridian Coast wheel of Fate costumes are definitely solo farmable but you will need other players for the ones in Moonwater Plains as they have too much HP. I won’t go too much detail into them since I assume you will encounter these naturally while leveling.
The sequence you will encounter them is Jiangshi –> Deva –> Stinger –> Lycan/Wolfskin –> Karri –> Profane. Jiangshi in Viridian Coast is farmable solo in your 20s while Deva/Stinger are best farmed solo in your late 30s/early 40s.
Red Mask (Level 10+)
You will need to farm Goldleaf Foundry in Gloomdross Forest for this. It has a chance to drop off the last boss (Dusk Adder Overseer Furin) but it is fairly rare so be mentally prepared to do 50+ runs for this.
Beast Hunter (Level 16+)
For this costume, you will need to farm Lair of the Yutay in Songshu Isle of Viridian Coast. It drops off the last boss as well but drop rate doesn’t seem to be as bad as Red Mask.
Bandit Queen (Level 16+) – Gon Female Only
Only farm this on a Gon Female toon as the costume is not tradeable. It has a low chance to drop off the last boss of Adder’s Nest dungeon in Songshu Isle.
Ivory Specter/Red Specter (Level 25+)
These two costumes are obtained by farming Guard Insignias or Blackram Insignias while wearing the opposite faction’s uniform (Blackram Uniform or Bamboo Guard Uniform). They cost 30 Insignias if you have Premium Membership (use the Dragon Express button at bottom of your inventory) or 40 Insignias otherwise. If you are not a premium member, you will need to purchase them from the Viridian Valor Stone vendor next to the Windstride teleport location in Jadestone Village.
You can farm the Guard Insignias in Jadestone village but really the best spot to farm them is in Sentinel Coast area of Songshu isle. Keep killing the guard/pirates and after about killing 10 of them a mini boss will spawn that will drop 2 of the Insignia each time. This goes faster in a group but if you are level 30-40ish you can solo them quickly.
Tyrian Cultist Uniform
Drops off any of the Tyrian Cultist mobs in Cinderlands. Not that too rare of a drop so you should hopefully have one or more if you just do the quests in the area.
Pugilist (Level 36+)
This costume drops off The Playpen mini dungeon in Scorching Sands. Much like the other drops, it comes off the last boss encounter.
No Worries (Level 36+) – Jin Male Only
This costume also drops from the same boss in The Playpen dungeon. Make sure to farm it on a Jin Male as this costume is not tradeable.
Obsidian Serpent/Black Veil/Cap (Level 36+)
One of the most popular costume/adornments to farm. The costume looks slick and the adornments looks great for any assassin/ninja looks. To farm this, you will need to complete Act 2 Chapter 30. You will then unlock the daily mission from Gunsang at the door called Enroaching Shadows. The costume drops off the last boss so what you can do is let the NPC die in the end of the mission to the boss. If the boss doesn’t drop anything, simply exit the instance and re-enter to repeat it. If the NPC survives, just abandon the daily mission and reacquire it. Be mentally prepared to run this daily mission up to 100 times if you want everything.
Crimson Officer Uniform/Cerulean Officer Uniform (level 36+)
If you want to get the next level of Crimson/Cerulean Uniforms, you can farm these at Scorching Sands. You will need to equip your faction uniform and kill opposite faction NPCs. Eventually two mini bosses will spawn and killing them will drop Insignia you can exchange with your vendor at the camp. The NPCs are not hard to kill but you will probably want to team up for more efficiency. Also watch out for hostile players from the opposite faction.
Talus Dominion Uniform
Talus Dominion mobs in Moonwater Plains drop this costume. Drop rate is a bit like the Tyrian Cultist Uniform.
Infinite Challenger (Level 43+)
This costume is not in the wardobe for some reason but it drops off Naksun boss in Dreadtide Arena in Sapphire Basin region. He is the last guy you have to face after beating all the rounds in the arena. This is a great costume for a Kung Fu Master.
Secret Agent (Level 43+)
While this costume is on Ncstore, it also have a low chance to drop off the Superior Combat Automaton mob in Talus Engineer Corps instance of Misty Woods. You need to pick up the daily quest from Chun Sanil in Skyhaven Perch to access the instance. Do the instance until you get to the Superior Combat Automaton and then abandon the daily quest after you kill him if you didn’t get the drop.
Spirit Veil (Level 43+)
You can sort of solo this but probably helps if you have another player. Has a chance to drop off the Fetid Priest that spawns as part of the daily quest Far Worse Thing in Misty Woods Besieged Camp area in Moonwater Plains.