During Ten Chi Jin, if you do Fuma Shuriken -> Katon -> Doton, it's more potency, SO LONG as the mob is going to stick around for a while and you don't need the Suiton effect
Regular 633 + 720 + 360
Doton 633 + 500 + 720

Else you might see Ninjas do a Doton and immediately use Hide to reset their Ninjutsus before the Doton can get them aggro, this Doton is completely free! Though this is more of a dungeon thing