The other thing that will set the mood for your entire production? Physical styling, including makeup, wardrobe, props, and set decorations. Whether you go big or go small, these things will communicate the bulk of your story. You should iron these out in the creative planning stages, though the specific details and purchases can come later. But how your video looks can deeply affect its success, so make sure your stylistic choices match the story you’re telling and your ultimate marketing goals.
Professional cameras, like DSLRs, give you fine control over the manual settings of shooting video and allow you to achieve the shallow depth of field (background out of focus) that people rave about. While they're primarily used for photography, DSLRs are incredibly small, work great in low light situations, and pair with a wide range of lenses — making them perfect for video. However, DSLRs do require some training (and additional purchases) of lenses.