There is really no such thing as "commandments" when it comes to playing the piano. You will not sin if you don't follow these but your learning efficiency will be sacrificed and it will lead to slow progress.
All beginner piano players (even intermediate players) should keep these "tips" in mind. Developing a good habit in your piano practice routine is very essential in achieving results just like in learning any other skills.
I only included four tips which I believe are the most important ones. Write them on a piece of paper and place it in front of your piano to help you remember them when you practice.
This pertains to the lessons in the Novice Piano Program. I advise you to focus on one lesson as a time. After you have mastered it, that's the only time that you should move to the next.
This is probably the #1 mistake most beginners make when they practice. Even I myself am guilty of this one sometimes. How do you know you are playing too fast? You’re playing too fast if you’re committing a lot of mistakes. If you make this a habit, you are actually teaching yourself to play with mistakes as if these mistakes are really part of the song. Our brain is very powerful and whatever it is that you habitually do, your brain will remember it whether you like it or not.
Playing slow is the key. Don’t be in a rush to play the song at its normal tempo if you’re not ready yet. Once you can play the song perfectly in the slow tempo around 3 to 4 times, that’s the only time that you should increase the tempo. Keep this is in mind as this is very important in learning new songs.
Hands Together (HT) is when you’re playing with both your both hands. Hands Separate is when you play with only either your Right or Left Hand.
In learning a new piece, practice 3 to 4 bars with your Right Hand (RH) first. When you can play it confidently without mistakes, learn to play the Left Hand (LH) next. Once you can play each hand separately, that’s the only time that you should play hands together. When you play HT, it should be much slower than the tempo at which you can play HS. For example, if you can play the left hand at 90% of the original tempo, you should start with 50% tempo when you play HT.
I believe I need not to explain the importance of finding time to practice. Of course you will not learn if you will not practice. Make it a habit to practice even at least 15 minutes a day to learn the song exercises in the program and it would help a lot in your progress. Make it a part of your schedule. It maybe difficult at first since it's not yet a part of your routine but eventually you will get used to it.
Hope these things will make sense to you as you do your piano practice. Keep these in mind and it will speed up your progress.