Similarly, don't criticize a student's previous teacher, even if you think the student's preparation is wretched. Such a remark doesn't help the student feel confident about continuing study and insults the parent that he was such a poor judge of teachers.
If another teacher makes a gossip-tinged remark to you, perhaps hoping to draw your agreement or to elicit more "juicy details," say nothing (or "Hmmm." or "You don't say?") and change the subject.
A true professional is secure in her ability to carry out her job and need not tear down others to build herself up.
Your mother was right: if you can't say something nice, don't say anything at all.
If you circumvent copyright protection, you reduce income for the publishing house. If they don't make a profit, they'll go out of business, and then we won't be able to buy the materials we need.
The composer/editor/arranger also loses money when copyright is violated. Again, if there is no financial remuneration, these people will quit working, thus narrowing the range of materials that are available to teachers and students. The average royalty is 5-10% of the cover price. On a $5 book, that's 25 to 50 cents per unit. Is it worth cheating the author out of that amount of money?
2. Give 110% value for your fee.
3. Don't inflate your credentials.
4. Report all your income (including cash) and pay taxes due on it.
5. Don't solicit students from another teacher's studio, either overtly (sending a letter) or more subtly (hinting to the parent that the child would be "enjoyable to teach").
6. Don't claim as your own any student who has studied with you less than six months. Until at least this point, your influence on this student is not substantial enough for you to claim his successes were influenced by you and your methods.