Writing for a user persona means writing for a specific user. Set aside generalities. Write as those you are addressing an individual.
Use terminology that fits. Consider the level of education, the job description, attitudes, and everything that defines the persona. Use terms that they understand and that cater to their specific perceptions.
Write in a style that speaks to the individual persona. Consider age and level of education, but also consider the context in which they will be viewing your content. Does writing call for a formal and business style, or a more casual approach?
Consider the preferences of your persona. Having a persona is as much about making a connection to your users as it is about delivering information.
Write to the pain points of your persona. Think about what their real or perceived problem is, and give them a solution.
Write to the context in which your persona is accessing your information. Context can involve a variety of types of scenarios. Are they seeing your product for the first time? Are they returning for advanced information? They will be coming to you at some phase in their customer journey. Consider their context and write for it.
Consider how your persona will be consuming the information you deliver. Consider physical limitations, devices, online or offline, and environments.