Since it is always best to write or do videos about the very things that your customers are looking for, it is best to learn more about them to get ideas. One method that can work really well is to start a forum or get on a forum appropriate to your industry. People will post concerns and reply back with information that can help you discover a host of topics that are important to them. Once you get a better idea about these topics - you can write articles, and pursue article marketing or do video marketing. Again, the goal is to provide value to people. Give them something they are wanting to know more about.