Free Shipping Day Plus More Holiday Shopping Tips

Don't forget Dec. 15. It's the last day the post office promises standard delivery by Christmas. “Go thirty minutes after it opens,” says Mark Di Vincenzo, bestselling author of Buy Shoes on Wednesday and Tweet at 4:00. “The early birds who line up outside when it opens will be gone.”

Do hold out for Free Shipping Day (Dec. 17) for online gifts. Check participating retailers at freeshippingday.com.

Plus: Your holiday budget: How much to spend on teachers and sitters?

Don't automatically equate “free shipping” with “cheapest.” Our brains may miss that fact! We're more likely to click “buy” if we're offered free shipping that saves us $7 than if offered a $10 discount instead, says David Bell, Ph.D., a marketing professor at Wharton. Use nextag.com or pricegrabber.com to see how the bottom-line price compares across sites.

Do make that minimum. “If you can, knock several things off your list from sites that share one shopping basket,” suggests Jeanette Pavini, savings expert at coupons.com. Two to try: the Gap group (Old Navy, Banana Republic, Athleta) and Quidsi sites (toy store yoyo.com, diapers.com, and soap.com).

Don't lose track of what's coming when. Install the free Slice app and it'll track all your online purchases, organize receipts, notify you when orders ship, and even alert you if the price drops within the price-adjustment period so you can claim a credit. It'll ping you, too, to let you know a package is coming while you're out.