What tools would be helpful to maintaining your privacy online?

It depends on what you mean by privacy, and what your threat model is. You'll want to be familiar with the notion of threat model if you want to talk about this.

Let's define privacy as the user being able to discuss anonymously on the web without fear that their pseudonyms will be correlated with their real identity or with one another. Additionally, it is the user's freedom from behavioural analysis, regardless of the currently claimed identity.

Well, the measures needed to protect their privacy differ vastly depending on who they want to protect it against. Given a stable definition of privacy, the threat model still changes vastly depending on the user's designed opponent. Opponent A can be an array of private actors, from insurance companies to potential recruiters, the advertising industry, to their own company's hierarchy. Opponent B can be the user's family, spouse, and/or such and such real life social circle they're involved with. Opponent C can be a prying government that's potentially hostile, like China's.

The user needs to think of who is the most relevant opponent to their case, and how would this opponent go about breaching their privacy. From there only can they start thinking about which tools to use and how to adapt their habits. (Tools alone won't do.)