Resti Santiago has been studying astrology since 1991, while he was still in college. He also began his studies on astrology using books written by modern astrologers. At age 19, he got well-versed in the works of Liz Greene and Howard Sasportas (founders of Center for Psychological Astrology). He was fortunate enough to have worked at the Theosophical Society in the Philippines (TSP) in the 90’s. TSP housed the largest collection of books on modern astrology in the Philippines.
By 2000, Resti felt he needed to know more and he took a formal course on Financial astrology, an application of modern astrology, under Kaye Shinker. He finished a three-level course on the subject. Shinker was one of the very first supporters of his astrological timing guides, the prototype of which was developed in the early years of the 21st century.
In 2002, Resti was introduced to the older systems of astrology and was hooked into it since then. He has taken courses and lessons from Robert Zoller (Certificate on Medieval Astrology), Robert Hand (Spiritual Astrology), Chris Brennan (Hellenistic Astrology) and Gary Price (Horary Astrology).