It has been my experience that if you study art from only one source or one mentor, it may inhibit your own style. Every time you go to paint something the words of the teacher or mentor will come to you. This is sometimes good and sometimes not so good. We all have to develop our own style and subject matter. Art is like handwriting. No two are the same.
Learn off your mentor or mentors but don't copy them. Break out on your own. I have found that to be a very necessary step in producing worthwhile art. You can also learn from other paintings.
For example, how does that artist paint water? Learning how another artist paints water when you may have trouble painting water in a particular work is good practice. I have done this many times, not just with water, but with many subjects. So doing can give you a clue as to what your painting needs and how to paint it. Again, never copy another artist's work no matter what country you live in. It can land you in court.
