To me, personas are critical in the creation and functionality of websites, mobile applications, and anything with which humans have to interact. There is strength in numbers, and personas are the accumulation of all of the collected data, information from surveys, interviews, and the vision of the clients.
Using the personas and company goals, I want to decide on the features that are needed, if they are viable, and any further microinteractions to take into consideration.
I found it very useful to include the developers and stakeholders in the discussion and to try to merge the persona's needs with their input.
Design studios are sessions of time where you and your team sketch out specific pages of the app/site that you're remaking, and trying to figure out the best layouts possible while keeping with the brand. After a few sessions, you come together and decide on the final* layout.
When working with a team, design studios are the best method to finding and creating great layouts.
Chances are if you forgot an aspect of the design, someone else remembered it, and you can spend the next.
*Nothing is really final until after testing.
Creating low-fidelity wireframes based off of our design studio sketches is one of the quickest way to test out the UI within the site.
Iterations are much easier on low-fidelity, and the high-fidelity mock-ups can be built on top of them.