MAB: Cosmos, Beyond, Ultimate
Regen/Def: Vicissitude, Stronghold, Mounted Champion
Regain: Sea Daughter

A mix of those (depending on how much Regen/Def you need to stay alive) is great. With some PDT and other defensive gear and Phalanx, many mobs will hit for 0. Requires capped (or near capped) Enhancing Magic. Then grab 50 mobs and spam Cataclysm and farm your own EXP/TE/KI.

PLD can also solo many mobs (if only slowly) with some Regen/Def Atma alone. Could even do RR, GH, MC, would be enough to keep you alive in most cases. PLD is a great job to solo lower NMs on, because it has most red and blue triggers natively available to them. Subbing THF also helps a bit, even more if you have an augmented Tarutaru Sash. As long as you don't mind slightly longer fights, you'll be surprised (and amazed) at how well PLD fares in solo situations, even against NMs.