Make a huge den out of duvet covers, chairs, sheets, pegs, blankets, cushions etc
Large cardboard box (draw on or cut doors and windows)
Play shops: display tins, fruit, cereal pkts on small table (even better if you have play cash till but can make one out of old box with long receipt that you can pull through a cut in the cardboard), lay out basket, bags, play money (again can make yourself). Each child dresses up in different hats/coats and pretends to be a different customer. Each child takes turn as cashier.
Play schools: use soft toys as pupils and DC are teachers
Indoor teddy bear picnic and serve them with play doh meals on paper plates: eg sausage, peas and chips or spaghetti with tomato sauce or play dog cakes and fruit
Get out stainless steel pans and serving spoons and metal sieve and plastic bowls and jugs on a rug or sheet with a selection of dried pulses such as lentils and split peas and dried pasta and let them play alone (but under supervision)
Toddlers like putting pulses like large dried haricots in to each indent in a muffin tin or jam tart tray
Large roll of paper such as back of wallpaper. Cut long strip and attach to hard floor with masking tape. Let them draw or paint or stick things on it. Older DC can lie on it while you draw around them and then fill in their own features and clothes etc.