4 ideas
Because film stock was the scarcest resource, he rehearsed scenes extensively beforehand so most shots needed only one or two takes. He also wrote around what he already had, using real locations he could access for free, including his parents' house.
Nolan finishes his films on schedule and on budget, and that record is what lets him negotiate for original, expensive, idiosyncratic projects that studios would otherwise refuse. Each disciplined delivery lowers the financier's perceived risk on the next film. That turns operational reliability into leverage for autonomy, for example getting Inception made after The Dark Knight.
Nolan runs sets with few layers between him and the work. He bans phones, keeps the crew small, avoids second units, and prefers shooting practical effects in camera over fixing them in post. Removing intermediaries and distractions keeps attention on the work in front of the camera. It also keeps decisions with one person and makes schedules predictable.
Nolan treats a film's structure as a way to place the audience inside a character's mind, not just as a way to order events. In Memento, scenes run in reverse, so viewers lack what came before, just as the amnesiac Leonard does. The form itself produces the experience the story describes. Asking 'how should the audience know things?' reveals design choices that plot alone hides.