Mold isn't inevitable in a bathroom — it just feels that way once you've scrubbed it off a corner and seen it return a month later. The fix is to make the bathroom a place mold can't establish itself. Three levers: cut the moisture, clean the surfaces, and move the air.
Ventilation does most of the work
The exhaust fan is the single biggest mold prevention tool in the room, and the one most people leave off. Run it during the shower and for at least twenty minutes after. If your fan is weak or you don't have one, cracking a window for fifteen minutes after a shower makes a real difference.
Squeegee the walls after a shower
It takes thirty seconds. Water that sits on tile and grout is exactly what mold needs to colonize. A small squeegee — they cost a few dollars at any hardware store — pulls the water off the tile and the glass door. Wipe the floor dry with a towel while you're at it.
A weekly wipe-down matters more than a monthly scrub
A spray bottle with a 50/50 mix of white vinegar and water, kept in the bathroom, makes weekly maintenance easy. After your last shower of the week, spray the tile around the tub and the corners of the shower, let it sit for a minute, and wipe. Vinegar is mild enough to use regularly without damaging grout or sealants.
Watch the grout
Grout is porous, which is exactly why mold grows there first. Once grout has darkened in places that won't wipe clean, it usually needs a baking soda paste and a stiff brush. For grout that's been neglected long enough to be permanently stained, regrouting the section is the honest fix.
The shower curtain and liner
The bottom edge of a vinyl shower curtain is where black mold almost always shows up first. Pull the curtain closed after every shower so it can dry fully, and toss the liner in the washing machine once a month on warm with a couple of towels (the towels agitate against it). Replace the liner every year or two — they're cheap and not worth gambling on.
When to call in help
If you've cleaned and dried and the smell still won't go away, the mold may be behind a wall or under a fixture. That's not a regular clean — that's a remediation job.