Has small medicine, deodorants, hair.
Baskets or trays. Try putting them away instead of being on the countertop cluttering up your space.
I took a cute little chest I found at Garden Ridge, could also get from Hobby Lobby, and put them in there. I used little plastic glasses and a clear lucite makeup organizer inside to separate certain things, too. I have done this for about 12 years, and all the mess is hidden. Of course I have a double sink countertop with plenty of room for it too. I hope this gives an idea of what you can do.
I bought wire racks--like the ones you buy for plastic wrap-- and attached to the wall inside the cabinet. Perfect for hair spray gel, etc. or curling irons, straighteners, or anything you want!!!!
I actually angled them towards the front so they are easy to get to..
I would not keep any medications in a bathroom, due to heat and humidity issues.
If you have vanity space, purchase multi tiered slide out shelves for the vanity base, for items that won't fit in medicine cabinet or in a hallway linen closet, or consider cutting a space between wall studs in a non load bearing wall, then add framing and shelves.