According to several government bodies and the CDC (Center for Disease Control - USA), the wearing of cloth face masks can help reduce the spread of COVID-19 and should be warn when in public.
Cloth face coverings should:
fit snugly but comfortably against the side of the face
be secured with ties or ear loops include multiple layers of fabric
allow for breathing without restriction
be able to be laundered and machine dried without damage or change to shape
CDC on Homemade Cloth Face Coverings
CDC recommends wearing cloth face coverings in public settings where other social distancing measures are difficult to maintain (e.g., grocery stores and pharmacies), especially in areas of significant community-based transmission. CDC also advises the use of simple cloth face coverings to slow the spread of the virus and help people who may have the virus and do not know it from transmitting it to others. Cloth face coverings fashioned from household items or made at home from common materials at low cost can be used as an additional, voluntary public health measure. Cloth face coverings should not be placed on young children under age 2, anyone who has trouble breathing, or is unconscious, incapacitated or otherwise unable to remove the mask without assistance. The cloth face coverings recommended are not surgical masks or N-95 respirators. Those are critical supplies that must continue to be reserved for healthcare workers and other medical first responders, as recommended by current CDC guidance.