Choose Your Weapons

• Professionals use pastry bags made of canvas -- very old-fashioned -- or varying weights of plastic, and occasionally twist up a cone of parchment paper for finely detailed work. Any of these three can handle very stiff batters or almost any kind of frosting, but that's not necessarily the case with sandwich bags. You can use a stiff frosting if it's well-beaten and fluffy, but you'll need to squeeze hard enough that only the sturdiest of sandwich bags will survive the pressure. Choose a light and fluffy frosting whenever possible, to keep things simple. In a pinch, you can double the sandwich bag for extra strength.

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• Prepare and cool your baked goods ahead of time, so they're ready to decorate once the frosting is made. Freshly-mixed frosting is usually softer and easier to pipe, as well. Spoon in at least 3 to 4 generous tablespoons of icing, as smaller amounts are harder to use. Squeeze the frosting into one corner of the bag, forcing out as much air as possible, then seal the bag. When you're ready to start piping frosting, snip off the corner with a pair of sharp scissors. Start with a small hole because you can always make it larger if necessary.

The Mechanics of Piping

• There's a definite technique to piping, and it takes a bit of practice. Twist the bag tightly, gripping the twisted portion with your dominant hand. You'll use that hand to keep a steady pressure on the frosting, and your other hand to direct the tip of the bag. Press the bag against the cake or cookie's surface to anchor the frosting, then squeeze and lift it away from the surface so the frosting falls gently to the surface. Picture making your pattern by looping a piece of string, rather than drawing it on with a marker. You won't press your bag to the surface again until you reach the end of each line.

A Few Quick Pointers

• It takes practice to be good at decorating with icing, but that doesn't have to break your budget. Lay out a sheet of clean wax paper or parchment paper, and practice writing or making decorations on the paper. When you've used up your frosting, scrape it up and fill new bags, and set out another sheet of paper to practice on. You can also use piping-bag tips with your sandwich bags, snipping a hole large enough to fit the tip and then filling the bag. With just a small starter kit of tips, you can make a wide range of decorations. Sandwich bags are also ideal for decorating with small amounts of multiple colors. Divide the frosting between bowls, color them separately, and then use each color to fill a separate bag.