Some say that call DestroyTrigger(GetTriggeringTrigger())
will cause a handle corrupt, that will eventually will make your game less efficient.
Better leave it as it is, or even Turn them off for accidentally fire the trigger most of the time.
For creating trigger via... trigger is not possible, I repeat, not possible. (local trigger ?)
Creating an empty trigger via Trigger Editor is reasonable and possible and when you want to add the Event, just do what Vlad had stated but mostly you will have a static Conditions and Actions.