Triangle Storage Cabinet in bathroom

We went to Home Depot or Lowes, and bought small round plastic paint buckets, that don't have handles. They fit perfectly, and we store our tooth paste, tooth brushes, and lots of other things in them. It still leaves a little room on each side of the bucket for larger items to stand up....like cans of deodorant, bottles of mouthwash, etc. In the top, space we have 2 small, stacking 4 drawer containers. They hold lots of little things. Pill bottles, chap stick, nail clipper/files, Q-tips, extra razors, etc.
Be sure to measure the depth of the space before you go shop for something that fits. If you have any type of 'container or organizer' store in your area, they always have lots of helpful small storage space items.