I use white vinegar to clean everything, its cheap as chips and does a far better job than the stuff that costs four times the price. It has anti-bacterial properties, cuts through grease and removes limescale (add two cups to an empty washing machine and run it at 60 degrees once a month to keep it clean and scale free). I also bought a steam cleaner (get a good one, I have a yellow and black german) and you will never buy cleaning products again as the steam does all the work, spray some white vinegar on the surface before you cover it in steam and you will never break your back scrubbing ever again.
Meal plan and batch cook.
Keep your receipts and make a list of what food you throw away and why.
Buy veg and fruit at the greengrocers, it lasts longer.
Buy plain yoghurt and flavour with mashed fruit, crumbled home made flapjacks or honey.
Cooking rice is easy. Place rice in saucepan and add enough cold water so that when you place your thumb in the pan, the tip of your thumb just touches the rice and the water reaches the thumb joint closest to the nail. Add salt and cook uncovered on a medium heat until you see little pot holes appearing in the rice, as soon as you see the pot holes, put a lid on the pan and turn the heat down to the lowest setting and cook for a further 10 minutes. Leftover rice is perfect for fried rice the following day and gives you the opportunity to use up any leftover veg that is still hanging around the fridge.
Don't buy oven chips, wash potatoes and cut them into wedges (don't peel them), add the wedges to a ziplock bag and add a couple of teaspoons of oil, salt, cayenne pepper, garlic and onion powder and dried herbs. Give the bag a good shake so that everything is covered in the oily seasoning, spread the wedges out on a baking tray so that they are not touching and bake in a pre-heated oven at 220 degrees for between 30 and 40 minutes (depending on the thickness of your wedges).
Limit the times you visit the supermarket and make a list before visiting.
Stop buying mini cartons of juice, buy reusable water bottles and fill up from the cheaper larger cartons of juice.
Buy washing powder and often used non-perishable stuff in bulk and when it is on special offer, I buy washing powder twice a year. This is going to sound sad but I know what I am willing to pay per toilet roll and per wash load, sometimes I'll see what I think is a bargain only to realise that once I've done the calculation, it isn't (I like Ariel so I only buy it when its at, or below, a certain price).
Grow your own herbs, strawberries, peppers and salad veg etc.
Make your own dried herbs for the winter months (see youtube).
Cut back on the snacks. I have home made snacks in the freezer (spring rolls, biscuits etc) and I eat less of them because most of the time I can't be bothered baking them.
Processed foods are generally nutritionally inferior (frozen veg and canned tomatoes are an exception), more expensive and have more salt, sugar and fat than is necessary.
Expand your cooking repertoire, cooking is an important life skill you should pass on to your kids and given the rising rates of childhood obesity, it could save them from all kinds of life limiting conditions.