What’s the specific and important technique for fulfilling the prayers?

Imām Ṣādiq (pbuh) stated:

A Muslim’s prayer for their brothers [other Muslims] in their absence, makes him to be safe from the calamities and gifts him God’s blessing. Also, the divine angels call him/ her, ‘You will be gifted twice the things, you prayed [wished] for your brother!’

دعا المسلم الاخیه بظهر الغیب یسوق الی الداعی الرزق ئ یصرف عنه البلاء وتقول له الملائکه لک مثلاه

(Shaykh Sadūq, Thawāb al A’māl, P. 153)

[In this regard,] Sir Ayatullậh Bahjat (mGbhs) often mentioned:

فلولا اذ جاء هم باسناتضرعوا

If we are indifferent [to the people] and do not pray for the calamities and predicament of the faithful people, the calamities will be attracted to us!’

(In the presence of Bahjat, Vol. 1, P. 97, point 139)

How much mercy God has on those who are not indifferent; cry, request, and supplicate God to remove these all calamities and disasters of Muslims and the faithful people! God stated:

 

(In the presence of Bahjat, Vol. 1, P. 187, point 278)