Bathrooms tend to be small, with little space between the bath, sink, toilet, and door. This limits the size of any piece of furniture you will be able to place in the room. Mainly, it will have to be narrow. This in turn means that you will be limited as to what you can place in the cabinet. There will not be room for bath towels for example, but small toiletry items (such as shampoos, lotions and creams), as well as facecloths and small towel will fit nicely.
Three examples – The one on the right looks like it will fit in a very tight space, but my fave is the Lakeside model on the left:
Narrow bathroom cabinets pictured:
Left: Lakeside Tall Storage Cabinet by Furniture Creations
Middle: Kyoto Double Bamboo Door Bathroom Linen Storage Cabinet by Furniture Creations
Right: White Bathroom Space Saver Cabinet with Wheels
It’s important that you decide where you will place your cabinet, and then measure that space. Once that is done, you can figure out what dimension your cabinet should be, and try to visualize if cabinet doors will be able to be opened fully, as well as drawers. The sink, a towel bar or even the bathroom door could stop you from doing this properly. You should know what items you will be placing in the cabinet, in order to buy a unit that best suits your needs.
Three more examples – each very nice IMHO:
Narrow bathroom cabinets pictured:
Left: Nantucket Cottage White Tall Storage Cabinet Shelf Unit by Furniture Creations
Middle: Slone Linen Tower Color: White by Elegant Home Fashions
Right: Slim Storage Cabinet by LCL
Take the height, number of shelves and space between shelves into account. This will determine what can be stored in the cabinet. In some units, shelves are adjustable, while in others, they are not. Another thing to consider is color. White is a good bet if that is the color of your bathroom. One of the advantages of white or pale colors, is they are not as noticeable, whereas a dark piece of furniture, especially if it is tall, can look imposing. But mostly, you want a color that will integrate itself well in the color scheme of your bathroom. You could also consider wall-mounted narrow cabinets. Their main advantage is that they take up no floor space at all. This is especially handy in very small bathrooms. Their disadvantage is that they require installation.