On the other side, I decided to use these small bins, attaching them to the vanity door using command hooks. This was a good non-committal option if I wanted to change it down the road. To hang heavier items, I used larger command hooks down the side of the cabinet. Again, maximizing vertical storage options.
Lastly, I wanted to minimize having to squat down and reach into the back of the vanity for products in the way back. Nothing like being late for work and having to go hunt.
My solution was to make a Double Tier Lazy Susan. It works perfectly in this space. It allows me to have easy access to all the things. No more frustration of rummaging through various things looking for what you want. Just give it a quick spin and there it appears!