How often you should wash it if it’s not disposable?
Much depends on how and where you have worn the covering, but generally daily is a good guide for re-usable coverings.
How often can you wear the disposable ones before throwing them away?
This should be after every use, but you may have only used it for a few minutes, for in which case you could remove carefully and keep out of the way for 72 hours before using again. Don’t re-use if dirty or damaged.
If you’re using it more than once during the day and taking it off, where do you store it/how do you stop it contaminating your handbag?
Keep the covering in a bag folded over so the inside surfaces touch each other, and the straps are at the top. Then when you get it out again, pull it out by the straps.
What hygiene should you practise before taking it off/putting it on (ie wash your hands etc) – is there a particular way you should fold it?
Always wash your hands or use hand sanitiser before putting a face mask or covering on. Don’t drag it over the face, but put it on over the mouth and nose and then loop the elastic round the ears. If you have the type of mask with elastic that goes over the head, hold the mask in place whilst you put the straps over your head. When you wear it, try not to fiddle with it. If you do touch it, sanitise your hands. When you come to take it off, sanitise your hands first, then remove carefully, not dragging over your face. Fold it with the inner sides together and place with the loops upright in a clean bag. Then wash or sanitise your hands again.
If you have a number of coverings, you could keep them for 72 hours before laundering normally, or if you want to wash daily, then wash at 60C. You may want to use a saucepan and some detergent rather than use the washing machine for just a small wash. A food thermometer would tell you when your water temperature is 60C.
Please look at this useful infographic from The World Health Organisation about how to wear a non medical face mask safely – https://www.who.int/images/default-source/health-topics/coronavirus/clothing-masks-infographic—(web)-logo-who.png?sfvrsn=b15e3742_16