I love a good system, and not every household needs the same.  So here is my take on organising all the items in the bathroom in a modular way.

Print the blocks you need for toothbrushes, toothpaste, cotton buds, toothpicks, electric toothbrushes and heads, cotton rounds, and any other things you may need. There are blocks that have drains in the bottom for the wet stuff, to make them easier to clean. Blocks with solid bottoms for the dry stuff. Print them in different colours for different members of the house hold, or all the same to get the look you want.

There are accessories for some of the blocks, like a toothpaste squeezer, or a divider with raisers to get your consumables sitting just right.

Once you have all the blocks you need you can choose to have them all in a line, or in a deeper block. The back covers have screw holes in so you can mount it on the wall, or you can attach the blocks back to back with the handy back to back adapters. Then to finish off you just need to add some end covers to hide the connectors and you're done.

All the blocks slide together with rails for a solid fit and have a reassuring click at the end to stop them coming apart accidentally.

Other blocks are on their way, which will be available in this collection.  

In the raw model files you'll find a blank block which is the correct size with all the connectors in place, so you can open it in an editor and cut out the shapes you need to hold your own special items.  For beginners I recommend Tinkercad which is free and really simple.