For some reason this always seems to stir up controversy, but I feel like most people who are natural born empaths are in fact undeveloped telepaths. The first step towards being able to read someone elses thoughts is to first learn to read their emotions. Thoughts are the ideas and instructions we encounter in life based on our emotional state of mind. When you're scared you'll have thoughts about safety and self-defense, when you're sad you're more likely to have thoughts that are aggressive or self-critical... it's basically like that.

You have to actually know someone well enough to be able to predict their patterns, because at it's core the art of empathy and telepathy seem to be more about reading queues than any silly notions of intercepting thoughts and brain waves and translating them into information. Some people might think this is "cheating" because it's not like Hollywood portrayals of telepathy, but it's still basically the same thing, and all that really matters is the accuracy with which an individual can read emotions and by extension, thoughts.