Ok, bathrooms may tend to be places where regular cleaning is sometimes neglected and it really shouldn't be but I really enjoy working in them. They are my favorite space to organize! The reason is that most people have the same types of things in the bathroom and things that don't fall into those regular categories are often destined for the "put elsewhere" bin or the "recycle/trash" bin. Everything that stays in the bathroom is grouped together according to type (e.g., hair care, skin care, eye care, nail care, medication, etc.). Next we determine where each category should be placed/stored (typically determined by how often used). And for the grand finale....we measure drawers and cabinets and find or buy containers that keep likes with likes and make each item as accessible as necessary.
One noteworthy tip, if you don't travel frequently I recommend putting makeup in a drawer with a drawer divider (something like the photo below). It is much more accessible than digging through a makeup bag every morning.
Happy bathroom organizing!