Peeler or Knife

• When you need to peel and cube hardy vegetables with a thick skin, such as carrots, potatoes and squashes, as well as firmer fruits like apples, you can use a sharp paring knife or a peeler. Both work well, so the choice comes down to a personal preference. Peelers remove only the thinnest layer of skin, thereby reducing waste; paring knives are more flexible. Whichever tool you use, you'll develop your own peeling technique to get the job done -- removing the skin in a long spiral, small pieces, long slices or a combination of all three. Soft fruits and vegetables with thinner skins are usually better peeled with a knife than a peeler, or using another technique. The knife or peeler must be sharp -- a dull peeler will fail to do its job, and a dull knife is hazardous.

Peeling by Hand

• Bananas and citrus fruits are easily peeled by hand before eating, but there are some vegetables that are easy to peel by hand too. Members of the onion family, including green onions and leeks, are peeled by removing their outer layers. Slice off the root end first to make it easier. Lettuces, cabbages and Brussels sprouts also just need to have their outer leaves pulled off, if necessary. Mushrooms don't always need to be peeled, but if you want to peel them, their thin, outer skin will brush away easily with your fingers.

Special Techniques for Peeling

• Tomatoes, especially when they're very ripe, are tricky to peel with a knife. Instead, pierce the skin in a few places with a knife then plunge them in a bowl of boiling water. After a minute or two in the water -- not long enough to change their texture -- the skins wrinkle up and brush away easily with your fingers. The same technique works for peaches and nectarines. Avocados, mangos and some other stone fruits can be peeled and cubed at the same time. Slice avocados in half and remove the stone; with mangoes and stone fruits, slice the "cheeks" off the sides and cut as much flesh as possible off the stone. Score the inside of the pieces vertically and horizontally down to, but not through, the skin. Gently push on the skins to flip the pieces inside out, revealing a grid of fruit pieces. Slice the cubes off until all that's left is the skin.

Cubing

• Unless you're using a recipe that specifies a size for the cubed pieces of fruits or vegetables, you can choose to make them any size you like. They should, however, be as evenly sized as possible, and small enough to eat in one bite. The rounded edges of fruits and vegetables make it impossible to perfectly cube every piece, so just cut pieces that are as cube-like as possible. You'll generally need to slice the item in half to give yourself a flat base, cut the two halves into plank-like slices, cut those slices into narrow French fry shapes, then stack those shapes together and slice them into cubes.