Silence — Shtikah — שְׁתִיקָה
Before you open your mouth, be silent and reflect:
"What benefit will my speech bring me or others?"
Cheshbon ha-Nefesh (“Accounting of the Soul”) is a step by step approach to improving one's characher traits. It was written by Rabbi Menachem Mendel of Satanov. It was published in 1845 with the encouragement of Rabbi Yisroel Salanter. The book is available from Feldheim Publishers.
Orchot Tzaddikim (“The Ways of the Tzaddikim”) is a book on Jewish ethics written in Germany in the 15th century, entitled Sefer ha-Middot by an the anonymous author, but called Orchot Tzaddikim by a later copyist. The book is available from Feldheim Publishers.