Carpet freshener
An easy way to brighten and spruce up a dull carpet, is to sprinkle a thin layer of borax over it. Let it sit overnight, then vacuum it well the next day. Another version is to add twice the amt. of corn meal or cornstarch to the borax and treat the carpet as above. Or, add 4 Tbs. reg. baby powder and 3 Tbs. cornstarch to a cup of baking soda and treat the carpet as above.

Carpet stain removal.
A good general carpet stain remover is foamy shaving cream. Simply apply a blob to the area. Rub it in well with a sponge and then rinse the area off with clan water. Let dry overnight and vacuum the next day. Waterless hand cleaner is also a good way to clean up stains like oil, grease and even tomato-based messes.

Coffee and tea.
Blot as much of the spill with paper towels, then apply distilled white vinegar to the area. If the stain persists, use a blob of foamy shaving cream on the stain, rub it in with a sponge and rinse off with water. Let dry and vacuum.

Chewing Gum & Wax
Freeze stains such as chewing gum and candle wax with ice or commercially available product in an aerosol can. Shatter with a blunt object and vacuum before the chips soften. Follow up with solvent.

Blood
Hydrogen Peroxide on a cotton ball dab it on use a paper towel to wipe it up.

Last but not least Pet Accidents.
Pour a liberal amt. of club soda on the area and blot immediately with paper towels. If the odor is still there the next day, cover the area with about 1/4 inch of baking soda and let it sit on the carpet for 2 day, then vacuum.