Priority one is getting Body and Mind and Clear the Mind active and maintaining them. This means that combat will generally open with your action skill from as close to maximum Guardian Angel range as possible. Clear the Mind will allow you to ignore elemental matchups as long as they are not outright immunities, greatly increasing the value of Flesh Melter and ensuring your bonus elements are always dealing at least neutral damage.
Body and Mind is a flat instance of damage that triggers once per instance of melee damage while it’s active. This means that a x14 Facepuncher with the 1 point in Infusion we have assigned will create 28 instances of Body and Mind assuming all projectiles land. Body and Mind inherits your action skill element, gets x31 scaling, and receives the following bonuses:
As such, while it’s active it serves as your main filler in between action skill activations.