Vocal harmonies are used more commonly than you might realise in all kinds of musical genres. Often their job is not to be overly prominent, but to enrich and fortify the lead vocal, providing a bed of sound to fill out the track. Ideally you will record them live but sometimes this isn't possible and at that point you can turn to software to help you. In this video from the course Vocal Tuning 101: The Art Of Vocal Tuning, Josh Carney compares and contrasts two approaches to creating vocal harmonies.
The first thing to consider is what type of music you are making. For acoustic or folk music, artificial harmonies might sound strange if not done correctly whereas in EDM they could be much more acceptable. Josh uses practical examples to show how auto-tuning lead and backing vocals or alternatively leaving them in their natural state can have very different effects. You'll hear how Melodyne - or a similar tool - can be used to create artificial harmonies from a single vocal part and then tweaked to make it sound more natural by automating volume over time. To learn much more about vocal tuning be sure to check out the full course using the links below.