A persona is a written representation of your end user. Persona is among the first method I used in user experience discovery process.
Persona helps me with empathy mapping. In every steps of UX design I will often refer to persona and ask such question as "What would she do in this moment?"
I rarely used only one persona and prefer less than three persona. It really gives me a clear picture of user expectation.
To be honest, wireframe is not my clients and superiors favorite. But it drives me crazy to design something without a proper wireframing beforehand. I love structure. and this method not only gives it, it weeds out bells and whistles of the feature that can easily accumulate as requirement.
You see people tend to put more feature to "make it better." But a perfect design is not when there is nothing left to add but when there is nothing left to put away.But of course, there is always budget constraint in a project. And I'm always open to not using wireframing if it has to take a budget away from other important UX activities such as UX research.