The first thing you have to remember with promotional video production is that while you are not going to try to replicate the pure imagery of the regular commercial, you still need to present things in a purely positive and aesthetic light. Often times a promotional video will end up taking the form of a documentary film, except it has some key difference. First, if there are interviews they are not natural and honest in any way. Instead, they are inspired, or even scripted. to say positive things about the subject. The images related to the subject, such as images of the product or location, are meant to look attractive and not necessarily focused on realism. This is not a natural view, but one that is angled so as to promote the subject in question.
When you are in production, and especially post-production, you need to make aesthetics the primary focus. In much of regular film production, the content, performances, idea, and other elements will actually take predominance over the style. Here, the opposite is true since the content is purely a sales pitch for an item. This does not, however, mean that you are going to be lying in the promotional video, but instead focusing on persuasion as in advertising and public relations. Use clean and dramatic lighting when necessary, make sure the promotional individuals and actors are well dressed and make up is applied, make the editing cuts quick and sharp, and make sure that color correction and motion graphics are included.