How do you get no experience in Pokemon Black?

In Pokémon Black, to reach a point of having no experience, you can intentionally avoid battling trainers and wild Pokémon. Choose to run from battles when possible, and avoid using Pokémon that gain experience. Additionally, you can use items like the Exp. Share strategically, or even reset your game to a very early save point where your Pokémon have not yet gained levels. However, keep in mind that this approach limits your progression in the game significantly.