One always starts any prayer, ritual and/or occasion by worshiping our Beloved Elephant God. One of the famous mantras dedicated to Ganpati follows:

(1)

"Vakratunda Mahaakaaya Suryakotee Sama Prabha
Nirvighnam kuru mey Deva, Sarva kaaryeshu Sarvadaa"

Vakratunda	curved trunk
Mahakaaya	large bodied
Surya kotee	million suns
Sama Prabha	with the brilliance of
Nirvighnam	free of obstacles
Kuru	make
mey	my
Deva	Lord
Sarva Kaaryeshu	in all work
Sarvada	always

O Lord Ganesha of Large body, curved trunk, with the brilliance of a million suns, please make all my work free of obstacles, always.

(2)
"Aum gam ganapataye namah"

This is a mantra from Ganapati Upanishad. One may always use it before beginning a journey, a new course in school, new career or job, or before entering into any new contract or business so that impediments are removed and your endeavor may be crowned with success.

(3)
Aum shri ganeshaya namah

This mantra is usually taught to children for their good education. It increases their memory power, and they become successful in their examinations. Of course, people of any age may use this mantra when taking courses in a school or university, and for success in attaining their degree.

(4)
Aum vakratundaya hum

This is a very powerful mantra, as discussed in the Ganesha Purana. When something is not working properly, individually or universally, nationally or internationally, or when the minds of the people turn crooked, negative, depressed or discouraged, the attention of Ganesha may be drawn by this mantra to straighten their ways. The HUM symbolizes "Delay no more, my Lord, in straightening the paths of the crooked-minded ones." This mantra is used many times in the Ganesha Purana to curb the atrocities of cruel demons. In addition, this mantra could also be used for healing any spinal deficiency, such as curvature of the spine or curved limbs. Dedicate 1,008 repetitions of this holy word to straighten and heal such deficiencies.

(5)
Aum kshipra prasadaya namah

Kshipra means instantaneous. If some danger or negative energy is coming your way and you don't know how to get rid of that trouble, with true devotion, practice this mantra for quick blessing and purification of one's aura.

(6)
Aum shrim hrim klim glaum gam
ganapataye vara varada sarva
janamme vashamanaya svaha

There are several bija (seed) mantras in this mantra . Among other things, it signals, "Shower Your blessings, O Lord. I offer my ego as an oblation."