When I pack up for the summer, I try to box up everything and put it in my closets. My classroom has large closets against one wall where students put coats and backpacks, so I'm lucky to have all that storage space for over the summer. There is also extra space above the closets I use as storage space throughout the year.
Since my room could always potentially be used for summer school, I put everything away that I can. Staplers, pencils, dry erase markers, etc. all get put in a box behind things in my closets. If they are easily accessible I know somebody will use or take them, and then I won't have them for my class the following year. And a lot of those dry erase markers I paid for myself! And those are not cheap!
However, there is a potential I could be moving classrooms this summer since our school is likely going to be seeing some grade level shifts (5th grade to middle school, 4K going full day, etc). If that happens I could go from the biggest and arguably nicest room in the building to one of the smallest, most falling apart rooms in the school. I don't trust our custodial staff to get all of my furniture to a new room. Our custodial staff is absolutely terrible.