It is hard to underestimate the importance of a teacher in deliberate practice.
Because deliberate practice aims beyond our current skill set, most people need a teacher’s help to recognize what to work on. Teachers are helpful in every field, but their knowledge is especially important for complex activities like dancing because there are so many subtle aspects that are very difficult to see until you have learned what to look for. For example, a beginning dancer can tell that west coast pros dance smoothly, but the actual body mechanics of how to create that look are extraordinarily difficult to break down from watching a YouTube video without extensive training.
In addition, teachers can be invaluable for designing practice activities because of their experience in how the relevant skills are acquired. Simply put, working without a teacher is like trying to reinvent the wheel (or, in this case, to rediscover the entirety of WCS on your own). The amount of difference that proper training can make is simply stunning. To put it in perspective, in the 13th century the scholar Roger Bacon claimed that it was impossible to master mathematics in less than 30 years. Today, college students regularly complete calculus, a level of mathematics that did not even exist at the time of Bacon’s pronouncement. The difference between then and now? We’ve learned an amazing amount about how to transmit the knowledge of mathematics.
At a certain point, an individual becomes capable of critically assessing their skill enough to create their own practice activities. However, even at the top levels of performance, it is common to see individuals seek feedback from others. Professional tennis players have their own coaches because the coach can help them understand how to approach a problem with their stroke, even if the player is skilled enough to know that the stroke isn’t working. Sometimes, what an expert needs is simply an outside perspective—someone who can see the action from the outside and pick up on details that may be missed when executing the action.
Fortunately, addressing this principle of deliberate practice is easy: take private lessons. Even seeing a local professional once a month, and seriously focusing on what they suggest, will transform your dancing.