In the book, The War of Art, author Steven Pressfield talked about what separates amateurs from professionals and how a professional became who they are.
I will write about what these aspects mean to me personally.
The professional is prepared
The pro strives to deliver a consistently excellent performance, day in and day out. He knows that if he is not prepared well, the Resistance will come at him from all different angles and tries to induce paralysis.
The professional does not show off
The pro’s work is unique with his own style, but he let others do the talking. His work will be so remarkable that other will choose to remark on it, so he does not have to.
The professional dedicates himself to mastering a technique
The pro knows there were many giants who came before him. Rarely someone will come up with an entirely revolutionary idea that is totally original, so he always considers himself a student of some grandmaster who came before. He also believes that mastery comes when he can refine his technique with a rich portfolio of skills.