If you buy or make your own cloth face mask, they can be reused as long as thoroughly washed beforehand.
In simple cases like getting on public transport, a face covering is all you need to keep relatively safe during the day.
Experts recommend this to be a scarf or a bandana wrapped around the mouth and nose, as opposed to a surgical face mask which should be reserved for medical professionals.
While no mask can guarantee someone not catching the virus, it will catch a lot more infectious airborne particles than if nothing was worn, therefore drastically increasing your personal safety.
Source: Daily Express