If everyone jumped off a bridge, would you? What if everyone was jumping off the bridge because it was “best practice”?
Since design is so subjective and experiences are so personal and there is such a wide variety of connectivity, form-factor, applied knowledge, and environmental factors that affect people in different ways at different times, it’s incredibly difficult to define a standard set of “best practices” that can be applied to experience design. Not only that, standardization can lead to complacency and creative stagnation, doing things a certain way because they are just done a certain way without understanding why they are done that way or if that is even the best way to do it. Everything can always be improved or done better or more efficiently or cheaper.
Best practice is thinking. Best practice is seeking perfection of form. Best practice is acting in the best interest of your client, stakeholders, and project. Best practice is being ethical and responsible. Best practice is inclusion and accessibility. Best practice is doing what is necessary to communicate the vision of the team. Best practice is understanding your audience.
Think of it this way:
Practice can be defined as the customary, habitual, or expected way of doing something. But it also means repeated performance of a skill to acquire or maintain proficiency. Get ready for the game.