When you are out at the supermarket, make sure that you don’t unnecessarily buy things you don’t need that will probably end up going off or wasted. Be realistic. You can also plan out your shopping for the things you will need in the week’s dishes and not just buying a lot of stuff blindly, that you may not use.All the groceries that need to be refrigerated, make sure they get in the fridge, and they don’t go off.
It's good to be aware of expiry dates but don’t take then too seriously if it's one day or two days over it's probably still fine, expiry dates are mostly just predictions, so use your own insight to see if it has gone off.
Take as Much as you will Eat
In the cafeteria or at home when you're serving yourself try to be reasonable with how much you take, then if you're still hungry go for seconds. Try to avoid leftovers, but if there are, store them. Also just be cautious of how much food you are taking and how much you are actually going to eat.
You can compost more than you may think you can. Apart from parts of fruits and veggies, you can compost egg shells, egg cartons or other forms of cardboard like toilet rolls, grass clippings, leaves, twigs, old flowers, tea bags, paper that isn't glossy coloured with chemicals, natural fibre cotton threads and sting, saw dust and wood chippings, ashes from wood or paper or charcoal, vegetarian pet feces, newspaper, even hair! (Don't go pulling out your hair, but if you cut your own hair or your dog's hair, dump it into the compost).