Many FX can happen within the engine itself, but you may find more control adding things like lightning, rain, lasers, and so on, after the fact. Programs like After Effects specialize specifically in fine tuned control for all manner of effects. Tutorials for almost anything AE related can be found online, usually easy-to-follow, that will allow you to lift the production quality once again.
Our goal is to provide video training courses for every aspect of the Unreal Engine movie making pipeline, from concept to completion. Please visit later.