Answered by Sayyidi Habib Umar bin Hafiz (may Allah protect him and benefit us by him)
Generally speaking, the word rabitah means any type of connection between one thing and another. More specifically it is used to mean the sincere connection of one’s heart to one of the people of Allah. It could entail bringing one’s Shaykh to heart in a specific way while reciting a certain dhikr.
By way of example, Habib Umar mentioned a method of istisharah, or consulting him in a spiritual sense. We can do this by doing the following:
1.Perform two rakats of nafl prayer
2. Recite the following prayer upon the Prophet ﷺ :
اللَّهُمَّ صَلِّ وَ سَلِّمْ على سَيِّدِنا مُحَمَّدٍ نُورِكَ السَّارِي وَمَدَدِكَ الجَارِي واجْمَعْنِي بِهِ فِي كُلِّ أَطْوَارِي وعلى آلِهِ وصَحْبِهِ يَانُورْ
Allahumma salli wa sallim `ala sayyidina Muhammadin nurik as-sari wa madadik al-jari w’ajm`ani bihi fi kulli atwari wa `ala alihi wa sahbihi ya Nur
O Allah, bestow prayers and peace upon our Master Muhammad, Your light which spreads and Your assistance which flows (throughout creation) and join me with him in all my states, and upon his Family and Companions, O Light!
3. Recite Surat al-Ikhlas, al-Falaq and al-Nas (3 or 7 times each)
4. Bring to heart the affair you wish to consult about and then waiting for the answer which manifests in the form of expansion or constriction in the heart.