Not perfect practice, but deliberate practice. For example, I practice sleight of hand (for card magic and cardistry). If I just practice, then whatever bad hab

Not perfect practice, but deliberate practice. For example, I practice sleight of hand (for card magic and cardistry). If I just practice, then whatever bad habits and mistakes I make, well I make them permanent. If, however, I, for example, video my practice sessions, watch them back and correct the mistakes I make, then I get better and my technique gets better. The point is to find out where you go wrong and correct for it.