The two-handed backhand is often easier to learn at first than the one-hander. Its advantages over a one-hander include requiring less arm strength, allowing both quicker preparation and a slightly later point of contact, and providing easier topspin production. The two-handed backhand does have weaknesses, though: it's difficult on low balls, it's very awkward for slice, and it doesn't allow as much reach as a one-hander.

Assume a right-handed player.

Key points:

Lefty forehand: One of the main reasons for the ease of learning the two-handed backhand is its similarity to a forehand. Thinking of it as a lefty forehand with the right hand just helping out is often a key to learning the stroke or to fixing a stroke that has gone astray.

Grip:
The most common grip combination for a two-hander is Eastern forehand for the left hand and Continental for the right, but plenty of variations have proven successful. Moving the left hand to a Semi-Western grip and/or the right hand closer to an Eastern backhand grip usually facilitates heavier topspin. Feel free to experiment, but keep in mind that you'll have to let go with your left hand now and then to reach very wide or short balls, and having your right hand in a reasonable position (Eastern backhand or Continental) to hit by itself is an advantage.

Footwork:
Having two hands on the racquet requires more precise positioning than using one hand, where you have more freedom to stretch if necessary. The great two-handers typically take lots of small steps to fine-tune their positioning. Take a larger final step toward the ball with your front foot to initiate your forward weight transfer.

Stance:
The square stance, where you align your feet so that a line from the back foot through the front foot runs parallel to the sideline, is easiest for most players, especially when learning the stroke. A more open stance (facing the net) is starting to show up among pro and other advanced players, and it may prove increasingly popular as has the open-stance forehand. One advantage to a more open stance is that it might feel freer to those players who find the classic stroking style constricting.

Backswing:
Some players use a little loop on their two-handed backswing, but there's very little argument for its necessity. Having two hands on the racquet makes it easy and quick to get the racquet back in the proper position, and two arms can usually generate plenty of power within a short swing path. Pull the racuquet back and down, so that the tip is pointing at the back fence. Laying your wrists back slightly should feel comfortable, and it will enhance your racquet-head speed.

Foreward Swing:
The two-handed backhand can hit flat, but you'll usually want to create some topspin, for which it's well suited. To create topspin, the low point of your swing must be below where you'll meet the ball. A foot or so lower is usually about right. Let your left arm execute more or less a forehand swing, with your right providing stability and added power. Transfer your weight onto your front foot just before you swing, but use both legs to push upward and forward as you swing. Brush up the back of the ball, meeting it roughly as far forward as your front foot. The two-handed backhand uses a significant amount of rotational energy. While your feet shouldn't move during the swing, your upper body can turn quite a bit, depending on your swing style.

Point of contact:
Meet the ball roughly even with your front hip.
Follow through: Appropriate follow-throughs on the two-hander vary from finishing out in front, with the racquet's edge pointing toward the net, to finishing with your hands over your right shoulder and your racquet behind your back. The more you use rotational energy from your hips and torso, the farther around your racquet will typically travel.