In the present day word, it is extremely difficult to get a proper mantra initiated by the right Guru. Time and distance are surely deterrent factors in mantra initiation. Mantra cannot be initiated unilaterally, without following certain minimum guidelines, which can be summarized as follows.
1. In the absence of direct contact between Guru and the aspirant, both should have a chance to know each other’s face. Without Guru knowing the aspirant or the aspirant knowing his or her Guru, any type of initiation will become futile.
2. Guru should get birth details of the aspirant such as place, date and time of birth and study the horoscope of the proposed disciple’s viṃśāṃśa chart (1/20) and find out which mantra will be more suitable for him or her. Not only the mantra, but also the deity and the capacity to meditate can be found out from D20 chart. If D20 chart is good, highest form of mantras such as Ṣoḍaśī can be straight away initiated. Once a mantra is initiated, it is difficult for the aspirant to change the mantra after some time. This should always be borne in mind, while finalizing the mantra for initiation. Based on the natal chart, an ātmabīja should be derived and imparted to the aspirant and the aspirant should be made to recite ātmabīja at least for a few days. If ātmabīja is perfectly derived, the aspirant will experience moderate bliss. If this bliss is experienced by the aspirant, Guru can guide the aspirant how to use ātmabīja. Ātmabīja cannot replace an existing bīja of a mantra, except in exceptional cases like Ṣoḍaśī. Certain mantras can be encased (sampuṭīkaraṇa) by prefixing and suffixing ātmabīja or Guru could advise the aspirant to recite ātmabīja daily for certain number of times without resorting to sampuṭīkaraṇa.
3. There should be minimal discussion between the Guru and the aspirant about the aspirant’s Iṣṭa Devata. As far as possible, mantra should be finalized for initiation, based upon the aspirant’s Iṣṭa Devata. Guru should also ascertain from the aspirant his religious and spiritual inclinations and ascertain his present spiritual status.
4. Once the mantra is finalized, an auspicious date and time should be finalized. Auspicious date should be fixed mainly based on tārābala and candrabala than other considerations. At the time of initiation, 8th house should be vacant.
5. Once the mantra is finalized, mantra should be forwarded to the aspirant by Guru. This should be done well in advance, so that the aspirant can go through the mantra and revert back to Guru for any clarification.
6. It is always better that Guru initiates the aspirant by verbally repeating the mantra and this can be done over phone. This should be done on the day and time fixed for initiation. This is one of the important aspects, as the aspirant should not make any mistakes while pronouncing the mantra.
7. Once all these formalities are completed, both Guru and the aspirant should sit together for meditation for a few minutes (ideally not more than five minutes). It is always advisable to inform the aspirant to fix his attention on his ājñācakra and Guru can pass on his energy to the aspirant using the available photograph of the aspirant. Guru will also meditate looking at the ājñācakra of the aspirant. If both Guru and the aspirant are in good spiritual level, transformation of energy can be realized by the disciple. Once this is done, Guru-disciple relationship is established.
8. It is natural that the disciple will have innumerable doubts during the initial days. Guru should have patience and knowledge to clarify all the doubts of this disciple. Once the disciple settles down with the mantra comfortably, Guru should periodically follow up with his disciple and make him or her advance in spiritual path. Guru should never have ego while training his disciples. There should be friendly approach between Guru and his disciples.
This is only broad guidelines for distance initiations and different Gurus adopt different methods.
Further reading : Guru and Mantra initiation