Is a Sufi shaykh's divination (khirah) that contradicts personal istikhara to be relied upon, and does the divination of shaykhs have a basis in religion?

It is Sunnah for a Muslim to perform Istikhara (prayer for guidance) for himself if he intends to undertake a permissible matter. This involves praying two rak'ahs other than a fard (obligatory) prayer, then reciting the Istikhara supplication, and mentioning his need. Istikhara is not permissible for others, nor are practices some people engage in, like opening books or the Qur'an for guidance, as that is not legislated.