More than 16.6 billion cards, letters and packages travel through the United States Postal Service each year between Thanksgiving and Christmas Day. To ensure that gifts and packages arrive safely and on time, the USPS encourages customers to take care while shipping and labeling packages.

"Boxes must be properly packaged to prevent any damage," said Mark Hnasko, a spokesman for the USPS. "Especially with fragile gifts, you want to make sure they are packaged correctly."

The best way to prevent breakage is to cushion fragile items with bubble wrap, packing peanuts, or newspaper so that they do not shift during travel, he explained. Wrap each item individually with bubble wrap or newspaper. Remove batteries from electronic devices and wrap them separately. Then close and shake the box if items move inside, add more packaging. If an item is likely to break, mark the package "fragile" in large print.

It's OK to reuse boxes, he adds, but all previous labels and markings should be removed or covered. To ensure that the box remains closed, use tape designed for sealing packages not string or masking tape. Enclose an extra address label inside the package in case the address label falls off.

"If you any questions or you're not sure how to package something, we'd be glad to help," said Hnasko. Customers can visit their local post office or go to the Web site www.usps.com [1] for help with packaging gifts, or call 1-800-ASK-USPS.

Properly addressing a package is equally important, he adds.

"You want to make sure it gets to its destination. You want to make sure that you have the correct Zip code, the correct address," said Hnasko. "Directional" terms, such as north and south, are a common problem for mailrooms. Also include the correct apartment number, if applicable.

Hnasko also encouraged customers to consider the Flat Rate Priority Mail box, which allows packages to be shipped for one flat rate regardless of weight. The smallest Flat Rate Priority box can fit a moderate-sized book or small electronic device, and ships for $4.95, he added. Large boxes work well for military care packages, and packages sent to an overseas APO/FPO address receive a discounted rate during the holiday season.

"If it fits, it ships. Anything that you can fit into that box, without altering, can be shipped for one low price," he said. "If it's something that is heavy, it's going to be the same low price for anything that you can get in there, up to 70 pounds." These boxes can be picked up at any post office or ordered online.

Customers with Internet access can go to www.usps.com [1] to view the latest mailing rates or calculate how much a package will cost to ship. You can also print postage and request next-day pickup at a home or business for outgoing packages, all without waiting in line at the Post Office.

"Many of the things you can do at the post office can now be done in the convenience of your own home," said Hnasko. "It's an added convenience, and it saves time. If you've never checked out usps.com, check it out and see what's on there. It's a valuable resource."

To ensure that your package arrives on time, plan ahead, said Hnasko. The holiday season is the USPS's busiest time of the year. To ensure that packages arrive by Dec. 25, Parcel Post mail must be shipped by Dec. 16. First Class letters and Priority Mail should be sent by Dec. 21. Express Mail and Drop Shipments must be sent by Dec. 23.

Military mail, Parcel Airlift Mail must be shipped by Dec. 4. Priority Mail and First Class letters and cards to APO/FPO addresses should be sent by Dec. 11. Express mail Military Service must be shipped by Dec. 18. The exception for these dates is APO/FPO AE ZIP 093: Parcel Airlift Mail must be sent by Dec. 1, and Priority Mail and First Class letters sent by Dec. 4.

International First-Class Mail should be sent by Dec. 11, or Dec. 4 for Africa and Central and South America.

For a more detailed listing of shipping cutoff dates, visit www.usps.com [1] and scroll down to "Holiday 2009 Mailing Dates."