A real preceptor or "Guru" or spiritual guide teaches souls hungering after truth or "Jnana" or knowledge that the superficial outward wanderings and religious and humanitarian activities can't take one to the realm of spiritual wisdom and bliss. Going to the Church every Sunday followed by butchering your co-workers (psychologically, to get ahead, that is) from Monday to Friday followed by Church-mongering again on Sunday is a worldly routine all-right, but it creates no substantial foundation for a truly spiritual life.
A real guide also does not impart true "knowledge" to those who are dull-witted, fully indulgent in objects of the senses, consider some people to be their friends and some others to be their enemies, etc.
"Suvicharana" is a compound word, or "Sandhi" of two words "Su" + "Vichara". "Su" comes from "Subhechha" and means good or righteous, and "Vichara" means deep thinking. After "Sravana" or hearing from the Guide, the "Jigyansu" or one who aspires to know starts doing "Vichara" or "Manana" or deep thinking on dualities like "Atma-Anatma" (Soul - Soul-less), "Jada-Chetana" (Dead-Alive), "Drashta-Drishya" (Observer - Observed),, "Nityanitya" or "Nitya - Anitya" (Permanent - Temporary). Where-as the material world is full of gray stuff (as opposed to black and white), the spiritual world requires one to discriminate (at least initially) between black and white, or good and bad, or real and unreal, etc. Based on this "Manana" or "Suvichara", the "Jeeva" starts realizing that my body is unreal, temporary, soul-less, a dead carcass; the "Atma" or soul which dwells in my body is real, permanent, alive; and the same "Atma" or soul or spirit dwells in the body of an ant, that of a human being, that of a Christ, that of a "Buddha", that of a god like "Brahma" or "Vishnu" or what have you, etc. The "Jeeva" realizes that this "Atma" or "Soul" or "Spirit" is all-pervading (the wise American Indians call it the spirit-that-moves-in-all-things), homogeneous like space, and "I am that Spirit."
The requisite spiritual practice for the Yogi in the Suvicharana stage is MANANA.