Make sure you wash your hands properly. 2. If you use a surgical mask, make sure the outside is green and the inside is white. 3. Bend the metal strips along the curve of the nose so that there are no holes left. 4. Avoid touching the middle of the mask when using and removing the mask. 5. Make sure the mask covers the nose, mouth and  chin perfectly. Also make sure the metal part is in the bridge of the nose. 6. Put on the mask strap well. If the mask string needs to be tied, tie the top first, then the bottom. 7. Dispose of the mask in the trash and wash your  hands thoroughly after using the mask.