I understand what you're getting at, it's not something I enforce, it's their Dad who makes sure that once ready for bed, rooms are clear as in nothing on the floor to accumulate, plus access to whatever they'll be doing in bed.
They have a bedtime between 8&9, it works quite well that they understand this is adult time once they're in bed. They can read, draw, write, do anything apart from using electronics, which is restricted, otherwise they'd be glued to their tablets non stop.
So whilst it's not something I enforce, like a folder and a couple of sheets of paper on the floor is no big thing for me, for their Dad he likes everywhere to be clear and tidy. They do get bonus pocket money for maintaining their rooms like this.
I'm quite messy, say if I had a letter I needed, I would know it's somewhere in said pile. Or if it's a book I know where I put it. Hubby has slight OCD I think, which isn't a bad thing most of the time. Growing up my room was a tip, so it's totally double standards.
I do believe if you want to instigate routines, you need to be clear and consistent. After all, these are life skills that are needed, instead of student digs looking like a war zone. Punishment like if it's not done or no progress has been made in 2 hours, then they will lose access to electronics for a period you see fit.
Possibly draconian, but effective.