Some messages and ideas are better conveyed in motion, so if you've mastered video production to a certain degree and see an opportunity to excercise it through any of the available applications, please take advantage of the advice below to ensure all your efforts pay off in a due manner.
Don't make a video that is on a par with a 'Lord of the Rings' movie length-wise: short videos (15 seconds or less) tend to show better results. Moreover, keep in mind that the video will appear in the Instagram or Facebook feed so aim to capture attention in the first few seconds.
While text and audio certainly compliment any video creative, avoid putting too much emphasis onto them: since many users scroll through their feeds with sound off, they are more likely to miss out on the point your are trying to make with sound. Even though text may partially compensate for it, keep it below 20% of the image in the thumbnail.