Student Accesibility
I believe in having all of the supplies accessible to the students. This does not mean that they can freely go take supplies from here, but it is accessible so that I can assign a student to help refill supplies and not have to open cupboard or take things down from a high shelf.

Routines – Keeping the Bins Organized
I have never had issues with students coming to these bins to get extra supplies without permission, but this is because I work hard at the beginning of the year to set up routines. One of my classroom jobs (Moniteurs des crayons) is the only person who is allowed to touch these bins, after asking my permission. It works great! The top bins get organized on a regular basis by students (Aide de classe, Moniteur des crayons, or Moniteurs des trousses).

Top Bins
The top four bins do contain supplies that the students can access as needed. These include pens and rulers, dry erase markers, and highlighters. When we are doing group activities, or when students are working in centers, they can access these bins as needed. In general, I will let the students know when these bins can be used.

This type of system works great for me, but I would love to hear what works for you!