Match it to the vanity below rather than the full wall. A cabinet the same width as the vanity or slightly narrower looks intentional, while one noticeably wider looks like it was chosen for the wall instead of the room. Sizes here run from 356mm through to 1200mm.

Leave roughly 15 to 25cm between the top of the vanity and the base of the cabinet, and set the height so the mirror sits comfortably for the tallest and shortest people using it. Check nothing on the vanity, such as a tall tap, fouls the cabinet door when it opens.

Most are a straightforward DIY job with the supplied fixings, provided you have solid backing to fix into. Plasterboard alone will not hold a loaded cabinet, so find the studs or use proper anchors. Anything with built in lighting or a power point needs a licensed electrician for the wiring.

They are built with moisture resistant finishes, but ventilation still matters. Run the exhaust fan during and after showers and leave the door open afterwards. Constant unvented steam will eventually lift edges and cause black spotting behind mirror glass in any bathroom cabinet.

A tall, narrow storage unit that stacks shelves or drawers vertically, usually only a few hundred millimetres wide. It is the answer for the strip of wall beside a vanity or behind a door, giving you real storage without eating floor space.

Yes. Tall, narrow furniture tips easily, particularly once the upper shelves are loaded, and a bathroom is a room where people grab for support. Use the supplied anti tip bracket and fix it into solid backing, and keep heavier items on the lower shelves.

Freestanding options that need no fixing, such as a tiered shelf unit, a slim tallboy or a floor standing cabinet. They come with you when you move and leave no holes behind. Still secure a tall unit with an anti tip strap where you can, since that is a small repair compared with the alternative.

Most ship flat packed with fixings and instructions. Mirror cabinets are commonly assembled with the doors to be fitted, and tallboys usually need building. Check the individual listing, and allow a clear space to work in since bathroom floors are rarely big enough for the job.

A bathroom is actually one of the worse places for it, since heat and humidity from showers can affect how some medicines keep. A cool, dry cupboard elsewhere is better, and anything needing to be out of reach of children should be stored high and locked regardless of the room.

Keep daily items at eye level and everything else above or below, and group like with like in small containers so the shelves do not become one deep pile. Adjustable shelves help here, since setting one shelf taller for bottles stops everything else being wasted space.