Conclusion

This is not an exhaustive list of best practices, but it's a good start. These are all subject to change as the web changes or I discover new things. You don't have to follow any of these, and the ones involving HLS, Dash and fallback urls involve more work, so you should consider the trade-offs when doing so. You're free to violate any of these as you choose, but doing so may result in getting a stern talking to (from me).

Feel free to reach out if you have any questions.