Dev...I would say yes to headphone monitoring and the HD414's are although low cost still provide a reasonable quality. Don't monitor at high levels because this can give you a wrong balance in your mix. It is however essential to check your final mix on good quality speakers and secondly on a small pair of less quality speakers because this will give an idea of what the average listener will experience.
Returning to the mix the following day when your ears are fresh will also give you a new impression of how successful your previous mix was.

Graham UK