Om Shree Gurubhyo Namaha

Agnihotra is a ritual mentioned in Vedas. Vedas are originated in India before the origin of any religion. Rishis(sages) heard the vedas and passed on them to their Shishyas(students) by oral recitation for many centuries. Later on they are written by Vedavyasa Maharishi.
Agnihotra is the ritual practiced exactly during the time of sunrise and sunset in the respective localities. Agnihotra is a fire ritual. Pure cow ghee and unbroken and unpolished rice in two portions is offered to sun god in the fire ritual along with recitation of certain mantras.
Materials Required: A copper pyramid vessel, stand for keeping the copper vessel, candle, matchbox, unbroken and unpolished rice, pure organic cow ghee, camphor and organic dried cow dung cakes are required to perform Agnihotra.
Directions to Sit: It is better to sit facing East in the morning sunrise Agnihotra and West in the evening sunset Agnihotra.
Procedure: Place a cow dung cake smeared with cow ghee horizontally on the bottom of copper pyramid vessel. Place few cow dung cakes vertically on top of the laid cow dung cake. In a small plate take unbroken rice grains and make it two portions and mix them with ghee. Lit the cow dung cakes in the copper vessel using camphor or else you can use a candle. Make sure the fire is burning. Note down the timings of sunrise and sunset in your locality. Prepare all the above mentioned procedure two minutes before the exact sunrise or sunset time. Now during the exact sunrise time take one portion of rice mixed with ghee with thumb, middle and ring finger and make an offering to the sun god saying the below mantra. Suryaya Swaaha. Suryaya Idam Namama. Next take the second portion of rice mixed with ghee and make an offering in the fire saying below mantra. Prajpataye Swaaha. Prajapataye Idam Namama.
Sunrise Mantras:

1. Suryaya Swaaha. Suryaya Idam Namama.

2. Prajapataye Swaaha Prajapataye Idam Namama.

If you are performing Agnihotra in the evening follow the below procedure. Mantras will change. Recite the below mantras for sunset Agnihotra.
Sunset Mantras:

1. Agnaaye Swaaha. Agnaaye Idam Namama.

2. Prajapataye Swaaha Prajaapataye Idam Namama.

Note: Leave the offering in the fire when you say swaaha in the above mantras. Timing of sunrise and sunset is very important in Agnihotra to derive maximum benefits.