Luckily, most common food stains can be treated with items likely to be found at home.
Berries: Stretch the fabric over a large bowl. Pour boiling hot water (straight from a tea kettle, for instance) through the fabric from at least a foot or less away (be careful not to burn yourself). Another trick is to rinse the stain with white vinegar, then soak it before rinsing thoroughly and laundering.
Chocolate Milk: Treat the stain with a diluted cleaning solution using an enzyme detergent, such as Oxyclean. Let stand for about 30 minutes, then rinse; repeat as needed.
Coffee & Tea: Using an eyedropper or cotton swab, rinse the stain with a solution of 1 part vinegar to 2 parts water; repeat as needed. Treat with a stain stick, then launder as usual.
Ketchup: Rinse under cold running water. Treat with liquid detergent; let stand for a few minutes before rinsing. Blot with vinegar; repeat as needed. Launder as usual.
Mustard: Scrape off excess, then run under cold running water. Treat with liquid detergent; let stand for a few minutes before rinsing. Treat with a stain stick, then launder as usual.
Oil & Butter: Sprinkle flour, talcum powder, cornstarch or artificial sweetener on both sides of the stain and let sit for 30 minutes. Shake off the powder; the stain should be faded or gone. Rub in some dishwashing soap and rinse under hot water; repeat as needed.
Soy Sauce: Blot stain dry. Using a cotton swab, dab the stain with white vinegar, then hydrogen peroxide, if needed. Ammonia can also be used, but should be rinsed immediately with cold water after the stain is gone. Rinse, then launder as usual.
Spaghetti Sauce: Rinse with cold water, then treat with laundry detergent for a few minutes before rinsing. Flush with white vinegar, then rinse thoroughly. Repeat with the laundry detergent and vinegar as needed.
Red Wine: Flush the stain with white wine, blotting dry between applications. Then flush with club soda, followed by white vinegar; repeat as needed.