Nothing makes it harder to enjoy a video than not being able to hear what people say (okay, leaving the lens cap on is pretty bad too.)
My friend Jay Rose, sound professional and author extraordinaire, sent along this amusing video showing how bad sound pulls you out of a video, and how to prevent it.
Great sound is not optional.
Any advice between using lavs and boom mics?
For do-it-yourself videos, the question is how many people will be talking. If only one person talks, you can use either. Purists prefer booms for quality, but it’s not a big deal to most ears. If you have more than one person talking, a boom can capture the conversation better because it’s easy to move from person to person during the shot (see video.)
High end professional productions almost always use both– the actors all have lavs hidden somewhere on their bodies, AND there’s a boom mic overhead.