"If you want to turn left, paddle more on the right." This is usually the advice provided to a first time paddler. And often it is all the instructions they will ever receive on the subject of maneuvering a kayak. Next to doing a simple forward stroke, efficient steering strokes are probably the most used skill by any kayaker on the water. It is unfortunate that so little time is spent on the subject. The problem with the "paddle more on the other side" technique is that with a lot of kayaks paddling more will just make you go faster with out actually doing much to turn the boat. In some situations where you want to stop a boat from turning one way, faster boat speed will actually accelerate the unwanted turn instead of stopping it. So, people try harder, making the boat go faster yet, until they get the turn they want, but instead of merely correcting the first turn, the over shoot and now have to stop from turning too far the other direction. More paddling on one side, more speed, another over shot, and eventual frustration. The reason for paddling on the opposite side from where you want to turn is you want to force the bow towards the direction you desire. The problem with merely paddling harder is even though you are applying the force on the right side, a standard forward stroke is designed to push the boat forward with maximum efficiency - i.e. minimum energy wasted trying to turn the boat. An efficient steering stroke for a kayak needs to be different from the forward stroke. The first step is to get the stroke away from the hull. Most forward stroke are kept in close to the boat to minimize the turing component - this is not universally true in that a "wing" paddle stroke starts out close, but moves away from the hull. A sweep stroke will start close to the hull, but immediately moves out away in a large arc and then pulls back in towards the stern. One principle of efficiently applying power with a paddle is you always want to keep the face of the blade nearly perpendicular to the direction you want the force to be applied. On a sweep stroke you want the blade power-face to start out facing out away from the hull and finish pointing in towards the stern of the boat. In this way, at the beginning of the stroke you are pushing the bow away from the paddle and at the end you are pulling the stern towards the paddle. The strongest part of the steering stroke is at the end where the paddle is pulling the stern. To get more power out of this, rotate your torso so your chest stays facing the paddle. Let your higher hand come across the centerline of the boat and aggressively draw the paddle in towards the stern of the boat just behind the cockpit.
I'll be in Madison, WI for this big paddle sports show. Come say "Hi"!