I'll add images later as busy in Sitheran atm.
This is mostly for those who never knew you can allow new groups for your roommates instead of allow everyone the same permissions.
Step 1: Open the house tab when at your apartment/plot and click roommates.
Step 2: Right click General User at the top.
Step 3: Click 'New Friend Group'
Step 4: Name it and set the permissions.
Step 5: Add the people you really want in that group.
NOTE: Since you can allow permissions such as decorate your house, add or remove non market items from the furniture bag etc. Please be cautious of who you add permission to since you are allowing that person to add and remove the items.