The Lace Method
Bring your own basket

The age of roommates has brought on an interesting dynamic.
In order to live in harmony, clutter, especially personal clutter needs to be managed.
A cluttered environment is often a point of baseline tension and the resulting actions can often lead to bigger disagreements.
People use chore charts and hold each other accountable but even that can cause tension.
A simple system can ease this with the baseline agreement that common spaces are everybody's responsibility but personal property need to be put away.
To start with :
Each roommate should get a nice basket, make a day of it and then make labels with your names. Feel free to match it with the aesthetic of your apartment.
The rule is simple, if the space is being used, leave personal items be, but if the space is not used for 2 hours or if you have someone coming over, personal items go in the respective baskets, always ask before doing this with paperwork. The mess doesn't bother anyone and at the end of the day - the baskets go into the owners room, at least outside their room.
This way, everyone works together to keep the place tidy but the individual items are the owners responsibility.