Question: A friend collected some seashells for me. Any suggestions on how to put them to use?

- Wendy Summers, Frametown, W.Va.

Martha Stewart: Shells make wonderful natural decorations. A bowl filled with small shells or a single large shell can adorn a table or bureau, or you can line up several favorites along a windowsill or the edge of a shelf.

You can also use shells in craft projects: Embellish the frame of a mirror, picture or bulletin board, a wooden box painted a color to complement the shells, a terra-cotta flowerpot or any other object that could use a little dressing up.

You can cover entire surfaces with shells, encrusting the object. (The flatter shells, such as scallops, can be overlapped slightly, for more complete coverage.) Or use shells just as accents: Glue them around the border of a flowerpot or attach just one exquisite shell to the top of a box.

A dab or two of craft glue is all you need to attach the shells. The way you arrange them depends on your collection. If you have lots of shells that are the same size, arrange them in an orderly fashion, creating rows, circles or spirals. If you have a more eclectic collection, glue them on in a random arrangement, for a more whimsical effect.

Always lay out the shells first to find a pleasing arrangement, then go back and glue them on one by one.

Question: What is the best way to remove candle wax from plush carpeting?

- Sherre Cullen, Evanston, Ill.

Martha Stewart: Wax on carpet looks worse than it is. Start by using a spoon to scrape up as much wax as possible. Place a clean white cotton cloth or paper towels over the remaining wax, and run a warm iron over the area; the wax will melt and the cloth will absorb it. (On synthetic carpet, make sure the iron is on the lowest setting.)

Repeat as necessary with clean cloths. If any color remains, dab it with dry-cleaning fluid, such as K2r or Afta, which you'll find at supermarkets and hardware stores. (Dry-cleaning fluids should be used in a well-ventilated area, and all stain-removal products should be tested in an out-of-the-way area first.)

Question: What is the difference between onions, leeks and shallots?

- Betty Tuttle, Oneida, N.Y.

Martha Stewart: These vegetables are all alliums (as are chives and garlic) and have an oniony taste, but their flavors vary considerably, as do their uses in cooking.

When we think of onions, we usually think of the white, yellow and red varieties found at any supermarket. Called dry or storage onions, they are air-dried after harvest, resulting in the papery skin that protects the moist flesh inside. Yellow and white onions generally have a sharp taste when raw and sweeten when cooked. Red onions start out sweeter and are a good choice for salads and sandwiches for those who like the taste of onions but not the pungency.

Pearl onions and boiling onions are harvested and dried when young and small and may be white, yellow or red.

Scallions, or green onions, are fresh onions. They have long, thin green leaves and small white bulbs. Many recipes call for just the white and light-green parts of the scallion, which have a mild onion flavor, but the greens are edible, too. Scallions can be eaten raw or cooked - try them on the grill this summer.

Sweet onions, such as Vidalias from Georgia, Walla Wallas from Washington and Mauis from Hawaii, are juicy, sweet and delicious raw. These and other varieties are increasingly available in specialty-food stores and supermarkets during their season in spring or summer.

Leeks have the appearance of overgrown scallions, with tough green leaves atop an elongated white bulb. Only the white and light-green parts are used; they have a light onion flavor and aroma. Leeks are an excellent addition to soups and sauteed dishes; or you can serve them on their own, grilled, braised, steamed or roasted. Ramps, or wild leeks, are smaller and have a more garlicky flavor.

Leeks must be cleaned carefully to rid them of the dirt that hides between their layers: Cut off the root, and slice the white and light-green parts into rounds. Fill the sink or a large bowl with cold water, and add the leeks; leave them for 10 to 15 minutes, allowing the dirt to settle to the bottom of the sink or bowl, then scoop out the leeks, leaving the dirt behind.

Shallots look like small dry onions with a papery skin that may be copper, golden or pale gray; the whitish flesh may have a hint of purple or pink. Shallots have a marvelous subtle flavor and can be substituted for onions in many recipes. Finely chopped shallots enhance a vinaigrette, and whole roasted shallots are a perfect accompaniment to a roast.