We have had some success lately with our swimmers by encouraging them to focus on their hand position in all phases of the stroke: the catch, pull, push and recovery.
We talk constantly about angles and leverage. It is nearly impossible to do a push up with your arms straight out in front of you. You don't have enough strength. The closer your hands get toward your shoulders the easier it becomes to push your body up. This is because of the angle and the leverage you have.
Similarly when we swim, if we get our hands in the correct position it is easier to pull ourselves forward because we have better leverage on the water. Simply stated, keep your knuckles facing the direction in which you wish to travel. Keep your palms facing the opposite direction - that which you have just come from. Keep your finger tips pointed toward the bottom of the pool during the catch, pull, push and the recovery as well.
Many swimmers want a long fluid stroke and mistake that to mean that their hands should glide out in front, extending the entry as far forward as possible. When we see swimmers like this at the pool we often think, "Look at how long and smooth that swimmer's stroke is". Well, it may be long and smooth but it isn't very efficient. One of our coaches likes to say that "Water you can touch, but cannot grab, does you no good".
Indeed that is true. When your fingers are fully extended, palms facing the bottom of the pool, knuckles to the sky, you cannot pull yourself forward.
So, slip your hand into the water and immediately get your fingers facing the bottom by cocking your wrist, bending your elbow keeping your shoulder and armpit up. Think of it this way...your fingers are below your wrist, which is below your forearm which is below your elbow which is below your shoulder.
Once your hand is in this position, first catch the water, then pull on it (in so doing you pull yourself over your hand) and finally push the water. At the finish make sure your palm is facing backward, your knuckles forward, your finger tips pointing to the pool bottom. When it is time for recovery, simply lift your hand out of the water by lifting your elbow, rather than "throwing" your entire arm forward from the shoulder.
Play with this and be willing to feel a little clumsy until you get the hang of it. Keep your knuckles facing the direction in which you wish to travel. This applies to all four strokes.
Let us known how it goes and if we can help in anyway!