Time Inc. Digital Studio

We’ve partnered with Saks Fifth Avenue and social networking site Foursquare to bring you styling tips on the hottest trends while you shop, plus the chance to score a free Bobbi Brown lip gloss, mascara, and how-to booklet! Sign up for an account at Foursquare.com, follow InStyle, and download the free app to your smartphone. Then take these three steps:

1) Visit a participating Saks Fifth Avenue store in Atlanta, Beverly Hills, Boston, Chicago, New York City, Phoenix, San Francisco, Short Hills, NJ, or Troy, MI.

2) Check in at InStyle-branded hot spots located in four departments throughout Saks Fifth Avenue—in Shoes, Beauty, WEAR and Women’s Contemporary—to unlock exclusive shopping tips from InStyle editors.

3) After visiting two or more hot spots, head to the store’s General Manager’s office, show off your check-ins, and nab that some killer Bobbi Brown products (while supplies last)!

Stay tuned through December for more check-in gifts from InStyle and Saks Fifth Avenue! Plus, if you’re still not quite sure about how to use Foursquare, click here.