I have found that you really only need a handful of products in your cleaning arsenal and they will cover pretty much anything (with a little elbow grease)
Baking Soda (Bicarbonate of Soda)- It cleans, deodorizes, scours, polishes and removes stains. It is an effective oven and hob cleaner and brings a shine to baths and sinks. It is also really good for your skin so kill two birds with one stone and put some in your bath, clean you and clean bath! It is non toxic to humans and can be used on most surfaces and fabrics (use it in the laundry to get rid of perspiration smells.)
Club Soda - Yes it is a drink but always keep a bottle handy as it lifts all sorts of stains, red wine, blood, and grease can be fizzed away from fabrics and carpets with Club Soda.
Essential Oil - Tea Tree and Eucalyptus are antibacterials and lavender is relaxing. All of these can be added to your cleaning products to leave a nice smell. Lemon added to an oven cleaner is lovely.
Lemons - Lemons are very versatile. They are antibacterial, will cut through grease and have a mild bleaching effect. Lemon juice also helps break down limescale.
Microfibre cloths - I picked mine up from Ikea for $9 for 4 cloths but they can be bought in any supermarket.
Salt - Salt pulls moisture to itself and so is useful for getting out stains from carpets. A pre-soak in salt water will help remove perspiration stains on laundry.
White Vinegar - Very useful for cleaning windows, mirrors and glass. Mix 50/50 with water and it is a multi-purpose cleaners. It can descale and when mixed with baking soda (Bicarbonate of Soda) it can clear blocked drains
I also have (but rarely use) Borax - It helps inhibit the growth of mildew and mould and removes grease and ketchup stains. It can be used as a laundry booster and is a useful disinfectant. Borax is harmful when ingested so keep it away from children and pets and make sure you use gloves when using it as it can be a skin irritant.
Ways to use them:
Sanitize your chopping board: Wipe over your board with the cut side of a fresh lemon (or lime).
To remove brown tea stains from cups: Mix some salt and White vinegar into a paste, wipe around the stain and rinse thoroughly.
Simple oven cleaner: Lightly spray oven with cold water, sprinkle a layer of bicarb over the oven floor, lightly spray with water again and leave to dry (or leave overnight). Spray again with water and use a sponge to wipe away. For tough areas use a palette knife or fine steel wool. Rinse well with hot water or spray a 50/50 water white vinegar solution to clean away the powdery residue.
Dishwashing without bubbles: Dissolve 1 tablespoon bicarb is a bowl of hot water and mix in juice of 1/2 lemon. There are no bubble but there will be clean dishes.
Remove Grass stains: soak garment in 50/50 cold water and white vinegar overnight, rinse and wash the following day.
Toilet Bowl Fizzer: pour 250ml white vinegar into the toilet bowl and scent with chosen essential oil (if you wish). Add 250g bicarb to toilet bowl, leave overnight. the next morning scrub with a toilet brush before flushing.
Remember that these products are natural and will need some elbow grease to get the same results as a chemical cleaner.