It is an art and it is a skill.
Nobody can learn to trash-talk, or practice trash-talking. It is something that people are just naturally good at, some more than others.
Some players have mastered the art of trash-talking and agitating in general. Sean Avery is known all around the National Hockey League as one of the best in the NHL, but sometimes, like most agitators or "goons," he crosses the line.