The USGA's ban on anchored putting will take effect on January 1, 2016—less than six months away. If you still anchor on the greens, or if you just like to experiment with different putting methods, I've got three effective techniques for you to try, all completely legal. Find the one that works for you, and not only will you be following the new rule—you'll be making more putts than ever.
THE LONG PUTTER
Just because the USGA has ruled against anchoring doesn't mean you have to toss your long putter in the bin. Use it as you normally would— just don't intentionally hold your top hand or the club against your chest, nor create an anchor point with your left forearm. Instead, move your top hand away from your body until the shaft is straight up and down and the heel of the putterhead is slightly off the ground (photo, below middle). Even though your fixed point is gone, you can still execute a reliable, straightback- and-through stroke using this technique.
THE FOREARM PRESS
This stroke requires a midlength putter and can be performed righthand low (photo, below left) or lefthand low. As you grip the club, press the top end of the grip against the inside of your left forearm, then secure it by clamping your right hand against the grip and your left arm. This establishes a legal, "below-the-elbow" fixed point. Matt Kuchar has been using a grip similar to this for several years, and he has seven PGA Tour titles to his name.
Your third option? Putt sidesaddle like Sam Snead used to do. A surprising number of my students who try this method love it! One advantage is that it lets you look straight at the hole when you set up, making it easier to aim your putter. My lower back isn't a fan, but if your lumbar region is in good shape, saddle up!