There are a few big mistakes to avoid. The biggest one is mixing vinegar with bleach or chlorine-based toilet cleaners. Do not do this. Vinegar is acidic, and bleach products should never be combined with acidic cleaners. If you recently used bleach, flush well, ventilate the room, and wait before using vinegar. When in doubt, do not mix products at all. One cleaner at a time is the safest rule.
Also, remember that vinegar is mainly useful for limescale. If the toilet smells bad because of poor ventilation, an old seal, or dirt around the floor and hinges, vinegar in the bowl will not solve the whole problem. Clean the seat, rim, outside, and floor area too, because smells often hide there. A fresh bowl helps, but the rest of the toilet matters as well.
Used the right way, though, vinegar is a simple and practical toilet trick. It is not glamorous, but it tackles a real household annoyance: stains that refuse to shift. With a soaked cloth, some patience, and a quick scrub afterward, your toilet bowl can look fresher without turning cleaning day into a full workout. It is a low-effort habit that can make regular cleaning easier.