White vinegar and spray bottle

For Countertops & windows
Combine a tablespoon of white vinegar and a quart of water in a spray bottle, squirt, and wipe dry. Vinegar is a mild acid that dissolves dirt, hard water deposits, and soap scum. (Be careful when using vinegar, which can irritate skin, eyes, and mucous membranes.)
Lemon juice

FOR FABRIC STAINS
Attack with white vinegar or lemon juice.
Baking soda

FOR FAUCETS & DIRTY OVENS
Sprinkle baking soda over the area (only when it's cool) and scrub with steel wool and water. The gritty soda scours off dirt and raises the pH of water, which helps remove chalky white buildup around faucets. (Avoid this abrasive method on glass stovetops.)
Baking soda and vinegar

FOR A CLOGGED DRAIN
Pour in half a cup of dry baking soda, followed by half a cup of vinegar, then cover the drain. Wait 15 minutes, then flush with two cups of hot or boiling water.

And keep in mind...  If you don't want to give up commercial cleaners, cast a skeptical eye on products labeled "eco-friendly" or "organic." Look instead for specific claims (such as "solvent-free" or "phosphate-free") and for the "Design for the Environment" label: These products have been carefully screened for their environmental effects.