In terms of principles for building out a level, one of the most important aspects of stealth level design is accounting for player freedom.
So it was a collaboration between level artist and level designer more than a level designer creates the whole level on its own and then gives it to the level artist.”
We were just here as level designers to help them: ‘hey, I just need that’ or ‘I really need this.’
Typically, a level designer will start by designing a prototype of a level or a blockout with these requirements in mind as they develop the scene.