Try to keep social content videos under 30 seconds. Pay attention to aspects unique to social media, like muted autoplay and video looping; you can actually use these tools to your advantage by playing with silent audio and creating seemingly endless loops. Also take advantage of highlighting positive customer feedback in your social videos — this increases your credibility and spreads positive word of mouth.
Extras are unique to your needs — you might benefit from behind-the-scenes footage, a quick photo session, or certain types of b-roll. Get it done! Any content you can create on set during production will only benefit you. It can add more long term value to your clients and give you more content to post. If you work with an agency, ask them what they can do. You might even ask for raw video footage so you can continue editing and repackaging your video for future use. Think about your needs and see what you can do!