In his book Outliers, author Malcolm Gladwell argues that it takes around ten thousand hours of practice to become a master within a field. That may be true, but the quality of the practice time is just as important. Dominic Reyes talks about a common mistake magicians make when they start to practice magic. They over do it:
It’s easy to believe that the best magicians practice every waking hour they get, but that’s often not the case. If you are new to magic, chances are that you currently have a level of obsession about it. In fact, that obsession may never go, but it could be getting in the way of you making progress. Spending hours at a time, every day, can cause burn out, leading to long breaks where you don’t feel like working on your technique at all. If you do stay motivated and continue to practice in long sessions, you may find that most of the improvement you get, comes from the first 10-20 minutes of each session, whilst you are fresh, paying attention, and motivated.
Having said that, you should practice EVERY DAY, but not for hours at a time. Long sessions of research may be effective, but when it comes to training your hands and mind to learn a technique, short sessions with plenty of breaks may get you better results in the long term.
The best magicians practice sessions often involves short, regular sessions of practice, with time in-between to recover, assess, and consolidate what you have learned.