Mantras
Mantras are the connectors of self to higher-self. Any yogic practice without a mantra is just mechanical. One should chant mantras with the attitude of completely surrendering self to the higher-self.
Sage Vaalmiki attained realization by chanting bija mantras 'Ma' 'Ra' continuously. When these bija mantras are chanted repeatedly it becomes 'Ra' 'Ma' which is the name of divine incarnation "Rama". Sage Vaalmiki did nothing other than this to attain self realization. He let-go of all other things.
There are many mantras each with specific purpose. Some mantras are strong and some are soft. Before proceeding to the strong mantras, one should purify self by soft mantras for years.
Standard Kriya Yoga was designed to suit ordinary person so, it adopted the softer mantras like ''Om Namo Bhagavate Vasudevaya", "Om Namo Bhagavate Rudraya" or "Om Namah Shivaya Shivaya Namah Om". When mind is sufficiently trained, one should move to strong mantras which yield the best results in short time.
The king of all mantras for self realization in "Maha Mrityunjaya Mantra". This is the Moksha Mantra. One should chant it regularly while surrendering self to the lord Maha Mrityunjaya with each repetition of it. By offering self to the divine completely with each reption of this mantra, one will attain self-realization quickly. This is the shortest route because it dissolves the ego unlike the other yogic practices.
Other yoga practicies as a byproduct will increase the lower ego consciousness, for e.g., after doing pranayama for couple of hours, one would think, today I did pranayama for two hours, I am great!. To dissolve this ego, one may need to practice another yogic technique.
Caution: Don't chant Maha Mtrityunjaya Mantra if you are non-vegetarian, it will give you adverse results (like accidents/death), which wouldn't be reversible.
Don't chant while attending nature calls (it is disrespect to Lord).
This mantra has the tendency to make one loose outer body consciousness and reflexes. So, don't chant while you are driving.
Lord Shiva is the supreme god for yogis. He is the creator of yogic science to uplift one towards self-realization.
Another powerful mantra is Gayatri Mantra.
Before jumping on to practice, learn the proper recitation of the mantra from the qualified sources.
Technique:
Relax, never ever press hard while practicing. Let it happen by itself, move with the flow. All through the process self-surrender, offer self to the lord completely.
Start from Muladhara, chant the mantra in the core of the Chakra, let the vibration of the mantra get filled in the Chakra. Slowly move up the Chakras one by one all the way up to Sahasrara while repeating this. After that, repeat this technique at all parts of your body one at a time. In the end, let whole body be filled with the divine vibration. Finally rest in the Third Eye (Ajna Chakra) reciting the mantra in the very essence of you. Continue recitation as long as you are comfortable in doing so.
kriya yoga mantras