The best piece of advice I can give you is centre your marketing video around a story and not the sale. Remember a majority of your audience will lose interest around the 10 second mark, so make it short and sweet. The worst thing to do is make a completely boring video, so lighten up. One of the most powerful methods you can use for video marketing is to educate your audience. Last but not least, make sure your video can be found by optimising it for search.