Hold the raiment extend button while the divine raiment is attached to an enemy, then enter a directional input to perform a raiment skill. A word of caution: the opponent must be toppled in order for the skill to be successful. Set and change your raiment skills from the menu.
Raiment skills are generally more strategy-based than fighting skills, and see Sakuna either use her raiment for extra mobility, or to weaken opponents. When a fight is turning out to be an uneven match, certain raiment skills can weaken the opponent and turn the tide of battle.
Take note that debuff-based skills can only be inflicted upon downed enemies, and that for some enemies, the directional input for a raiment skill must be held in order to apply. When a debuff is applied, there will be a coloured aura around the enemy, and text will appear over it, indicating a successful debuff.