The Pavamana prayer from the Brihadaranyaka Upanishad 1.3.28: lead me from untruth to truth, from darkness to light, from death to immortality.
The Upanishadic peace prayer 'Saha navavatu': teacher and student ask together for protection, nourishment, vigour and freedom from hatred.
The Ganapati Atharvashirsha (Ganapati Upanishad), an Atharvaveda-tradition text praising Ganesha as Brahman and the Self.
The Isha Upanishad, Yajurveda 40: eighteen mantras on seeing the Lord in all things, enjoying through renunciation, and joining knowledge with action.
The Mandukya Upanishad (Atharvaveda): twelve mantras on OM, the three states of consciousness and the silent fourth, Turiya.