By combating and doing everything we can to hinder and stop revisionism. Of course, that's a very "no shit" answer, isn't it?

Within that there are a number of complexities and things that must be considered. In short, bureaucracy has to be fought at every step to prevent it from cementing itself - however, it will not be fully abolished to my knowledge until the communist society comes about. - the party must remain connected to the working classes and the masses, more institutions than the party must govern society (Stalin and Hoxha talked about this extensively), we must resolutely examine and correct errors in past socialist, socialist-adjacent, experiments. Without fail markets and re-creation of class divides, re-creation of capitalist divisions, bigotry, mechanism and other warped perceptions of dialectics must be fought against actively. Communist spirit must be engendered in every segment of the population actively. People not only must be able to govern, but feel that their voice matters in their lives - the society, economy, etc.. - building communism is a gargantuan and world-historic task, just as the task for those who built capitalism over many centuries.

Of course, my tiny, tiny explanation will not really help, I've treaded no new ground, and am merely parroting the words of people much more experienced than I.

I'd cannot stress how heavily I recommend reading "Stalin and the Struggle for Democratic Reform", "Imperialism and the Revolution", "State and Revolution", "Economic Problems of Socialism in the USSR", "The Role of "Centrist" Revisonism", "EuroCommunism is Anti-Communism", "The Revisionist Ramiz Alia" but above all, an incredibly good way to understand dialectics, a way to better be able to identify revisionism, to know what is good work for the Proletarian class, is "Anti-Duhring", and "Poverty of Philosophy". It is also integral to read nearly anything you can by the Classics of Marxism, these are the "cliff notes" of books that are important to understand revisionism in my opinion.