I find curse very useful, sometimes ill cast that on a high level before attacking them with another weapon. Makes whatever weapon I select more effective.
What tends to lower reps is putting multiple points on a skill, making it more effective in battle, thereby making it easier to defeat enemies (fewer attacks) and then rewarding fewer reps because of the easier kill.
Notoriety, and Weapon levels themselves seem to have a greater impact on rewarded reps overall.
