Last minute holiday shipping

NEW YORK (CNNMoney.com) -- The deadline for getting your packages mailed out is fast approaching. Here's your survival guide to holiday shipping so you can get that last-minute present to your in-laws.

If you haven't sent out your holiday cards or priority mail yet, you have until tomorrow, Dec. 20, to get to a mailbox.

You can wait to get those packages in the mail as late as Saturday if you use Express Mail. The Postal Service will deliver Express Mail in most major cities on Dec. 24 and Dec. 25.

If you want to send something through UPS, check their schedule at UPS.com/holiday. You can wait until Saturday to use UPS next day Air service or FedEx Overnight. For more info, go to fedex.com.

Many Post offices have extended hours for the holiday season. Go to USPS.com to find out what your local post office hours are.

Of course, getting your gift to that special someone in the nick of time is priceless. But you should get a sense of just how much it'll cost.

Here are some numbers where you can get automated rate services: U.S. Postal Service, (800) ASK-USPS (275-8777); FedEx, (800) GO-FEDEX (463-3339); UPS, (800) PICK-UPS (742-5877).

You'll need ZIP codes, the weight of the package and what the gift's basic shape is so you can decide what kind of packaging you'll need.

To make sure your presents arrive safely, use a box that is designed for shipping, not moving according to UPS.

You don't want to go digging out those old boxes from your last move. You also shouldn't mail presents in the same boxes in which they were shipped.

You should also have at least two inches of bubble wrap or packaging peanuts. If you are shipping something that is perishable, put it in an interior airtight container or plastic bag before putting them in a gift box.

And before you close the box, put an extra mailing label inside. This is just in case the outside label gets damaged.

Of course there are some things that you can't send through the mail. This includes alcohol or other flammable liquids.

Some states will let you ship wine, but you should check with your post office or the retail clerk.

"If something is leaking, the package won't be delivered," says Joanne Veto of the US Postal Service.

If you want to send perishables, like fruitcake or cookies, you should send that priority mail and make sure you wrap it in cellophane and put it in plastic.