Before reading the psalms, it is traditional to say the introductory prayers to prepare the soul. These typically include: "Heavenly King" (Împărate Ceresc)
The Trisagion prayers ("Holy God...", "All-Holy Trinity...", "Our Father")
Troparia of repentance and a prayer to the Holy Spirit for enlightenment.
This catisma establishes the contrast between the righteous and the ungodly, while also celebrating God's majesty. Psaltire - OrthodoxWiki
This guide covers , the foundational section of the Orthodox Psalter. In the Orthodox liturgical tradition, the 150 psalms are divided into 20 sections called kathismata (catisme). 1. Opening Prayers (Rugăciunile Începătoare)