STICK ONIONS IN YOUR STOCKINGS
Onions will keep for months if they are stored in a way that lets air circulate, as this stops rot from forming in the dry skins.
A cheap method is to use a clean pair of lightweight, natural-coloured tights (thick, black tights will cut out daylight and may cause your onions to sprout).
Just cut the legs off and drop onions into the legs one at a time, tying a knot between each onion as you go.
Once the leg is full, hang it up in a cool, light and dry spot and snip off an onion from the bottom of the chain as and when you need it.
The circulation of air, light and moisture will keep your onions in perfect condition for up to six months.
WRAP CELERY IN FOIL TO KEEP IT CRISP
A tip from the Good Housekeeping experts: if you only eat celery a few stalks at a time, keep the rest in the crisper drawer of your fridge, wrapped tightly (but not sealed completely) in foil.
The humidity in the drawer and the tight foil will keep the celery moist and crisp while allowing the ripening gas ethylene to escape. This can keep the celery crisp for up to two weeks.
MIX APPLES AND POTATOES
Store an apple or two in a ventilated bag with your potatoes and keep them in a cool, dry place.
This will keep them from sprouting, due to gases emitted from the apple.
Source : https://www.dailymail.co.uk/femail/food/article-6210601/The-simple-hacks-help-fresh-produce-longer.html