Simple lock picking is a trade that anyone can learn. However, advanced lock picking is a craft that requires mechanical sensitivity, physical dexterity, visual concentration and analytic thinking. If you strive to excel at lock picking, you will grow in many ways.
Learning how to pull the pick over the pins is surprisingly difficult. The problem is that the mechanical skills you learned early in life involved maintaning a fixed position or fixed path for your hands independant of the amount of force required. In lock picking, you must learn how to apply a fixed force independant of the position of you hand. As you pull the pick out of the lock you want to apply a fixed pressure on the pins. The picks should bounce up and down in the keyway according to the resistance offered by each pin.
To pick a lock you need feedback about the effects of your manipulations. To get the feedback, you must train yourself to be sensitve the sound and the feel of the pick passing over the pins. This is a mechanical skill that can only be learned with practice. The exercises will help you recognize the important information coming from your fingers.
In order to excel at lock picking, you must train yourself to have a visually reconstructive imagination. The idea is to use information from all your senses to build a picture of what is happening inside the lock as you pick it. Basically, you want to project your senses into the lock to receive a full picture of how it is responding to your manipulations. Once you have learned how to build this picture, it is easy to choose manipulations that will open the lock.
All your senses provide information about the lock. Touch and sound provide the most information, but the other senses can reveal critical information as well. For example, your nose can tell whether a lock has been lubricated recently. As a beginner, you will need to use your eyes for hand-eye coordination, but as you improve you will find it unnecessary to look at the lock. In fact, it is better to ignore your eyes to your sight to build an image of the lock based on the information you receive from your fingers and ears.
The goal of this mental skill is to aquire a relaxed concentration on the lock. Don't force the concentration. Try to ignore the sensations and thoughts that are not related to the lock. Don't try to focus on the lock.
Each lock has it's own special characteristics which make picking harder or easier. If you learn to recognize and exploit the "personality traits" of locks, picking will go much faster. Basically, you want to analyze the feedback you get from the lock to diagnose it's personality traits and then use your experience to decide on an approach to open a lock. Chapter 9 discusses a large number of common traits and ways to exploit or overcome them.
People underestimate the analytic involved in lock picking. They think that the picking tool opens the lock. To them the torque wrench is a passive tool that just puts the lock under the desired stress. Let me propose another way to view the situation. The pick is just running over the pins to get information about the lock. Based on an analysis that information the torque is adjusted to make the pins set at the sheer line. It's the torque wrench that opens the lock.
Varying the torque as the picks moves in and out of the keyway is a general trick that can be used to get around several picking problems. For example, if the middle pins are set, but the ends pins are not, you can increase the torque as the pick moves over the middle pins. This will reduce the chances of disturbing the correctly set pins. If some pin doesn't seem to lift up far enough as the pick passes over it, then try reduicing the torque on the next pass.
The skill of adjusting the torque while the pick is moving requires careful coordination between your hands, but as you become better at visualizing the process of picking the lock, you will become better at this important skill.