When a recipe calls for adding oil, garlic, and onions to a pan, always add garlic last. This keeps it from burning and tasting bitter.

Use a hand blender to puree the soup.... it's easier than transferring it all to a food processor.

Leeks are generally full of sand and dirt that's hard to get at when they're whole. Chop them first, immerse them in cold water, and drain in a colander.

Mushrooms act like sponges and absorb lots of water if they're washed, instead, wipe them off with a damp cloth or paper towel to clean.

Never cook with any wine you wouldn't drink!

Don't add salt to the water when boiling corn on the cob - the calcium in the salt will make the corn tough.

If you've over-salted a soup, gravy, or stew, cut a raw potato into large chunks and add to the pot.  Remove after about 10 mins when the potato starts to soften. By then they should have absorbed the excess saltiness.

Add a pinch of sugar to tomato-based dished such as pasta sauces.  The sugar brings out the flavour of the tomatoes and removes any bitterness.

Keeping guacamole looking fresh and green is a challenge for any cook.  Because air oxidises the avocado so quickly, the only 100% successful method is to serve anything with avocado immediately after slicing or mashing.  But here are some tips that should help slow down or minimize the unsightly browning:

Make an airtight seal by covering the surface of the guacamole with cling film.
Coat the surface with lemon or lime juice.
Leave the avocado stone in the guacamole.
Soak the sliced/diced avocado in cool water for a few minutes before mashing.
Spread a thin layer of sour cream over the surface of the guacamole and stir in just before you serve.
Pour olive oil over the top to create a seal; pour off the oil when you want to eat it.
Remember, if the top of your guacamole does go brown it is still edible. Just carefully scrape off the surface.

While there doesn't seem to be one sure-fire way to prevent cutting onions from being such an emotional process, here are a few suggestions:

Try slicing the onion under running water into a colander in your sink. This should absorb the odors and makes for a less tearful day.
Freeze onions for about 15 minutes before you slice them. The cold will keep the eye-watering fumes at a minimum.
Carefully push a piece of bread up the blade of your knife toward the handle. When you start to chop, the bread should absorb the fumes that bring tears to your eyes.
Hold a slice of cucumber, bread, apple, or potato in-between your lips, half-in and half-out of your mouth while slicing onions. This way your eyes won't weep.
Light a candle close to your work area to absorb the onion fumes as you chop.

To melt chocolate without burning:  First, find a bowl that fits snugly into a pot without touching the bottom.  Heat (but don't boil) water in the bottom pot and place the chocolate, cut into small pieces, in the bowl. Stir the chocolate constantly as it melts to keep the heat evenly distributed.  Never add water to chocolate as it will ruin the batch. Watch out for moisture on any utensils you're using to stir the chocolate!

Freeze opened coconut milk into ice cubes to keep fresh. Add a few cubes directly from the freezer to the pot when cooking!

Wash spinach in salted water to get rid of grit.

Place an apple in the bag with your potatoes to stop them from budding before you get a chance to cook them.

Ripen an avocado faster by sealing it in a brown paper bag with a banana.  (Keep at room temperature.)

If you'd like to avoid grating off part of your thumb when a recipe calls for the rind of an orange, lemon, or lime try this: use a potato-peeler to take off strips of the rind and then mince finely with a knife.

To keep strawberries fresh, never wash until you are going to use them.  Also, wash first and then cut the tops off; strawberries will absorb the water like a sponge and go soggy!

Grind a little black pepper on strawberries a before serving to bring out the flavor; or, for the more adventurous, marinate them in high quality balsamic vinegar and serve with a soft cheese, such as mascarpone instead of cream!

Keep nuts fresh for up to a year by freezing them in a plastic container.  Remove some whenever you want and allow to stand at room temperature for an hour before nibbling.

To test an egg for freshness, fill a cup or bowl with water and gently place the egg in the water.  Fresh eggs will sink down to the bottom of the bowl. Semi-fresh eggs will stand on end and bob.  Old eggs will float and should be discarded.

If you would like to hard boil eggs and store them in the fridge then pop a tea bag or a few drops of food coloring into the pot with the eggs when cooking them.  This will color the shell, so you'll be able to distinguish the fresh eggs in your fridge from the hard boiled ones!

The easy way to marinate mess-free and effectively: Put the marinade into a ziplock bag with the meat, fish, vegetables, or tofu.  Hold the bag upright and make sure all the pieces have been covered with sauce. Then suck or press out all the air and seal the bag.  Using this method, the flavors are absorbed better, and you don' have to keep stirring your mixture. Plus, no spills!  Don't forget to put it in the fridge while marinating to stop bacteria from multiplying, and NEVER reuse marinade!

If you have some wine left over that you know you will not drink before it goes off, pour the remainder into an ice cube tray or bag and keep the cubes for cooking with later.  Red wine will be obvious but labelling white is probably a good idea if you don't want an alcoholic surprise some day!

Remove the smell of garlic, onions, or other smelly things like fish from your hands by rubbing them:

Against stainless steel under cold running water.
With a bit of before washing.  The salt should absorb the smells but be careful of little cuts - ouch!
With ground coffee or a cut potato.
With a cut lemon, - again, not recommended if you have any cuts on your hands.

If your garlic has been in the fridge for a while. make sure to remove the centre sprout of the clove (it goes green in older cloves).  This will stop the garlic from tasting acrid when cooked.

Working with filo pastry can be fiddly and time consuming.  Work with the pastry on dry, greaseproof paper; this will make it easier to pick up, move, or roll up.  To stop the remainder of the filo from drying out while you are assembling the dish, cover it with a sheet of greaseproof paper and cover that with a tea towel wrung out in cold water.