In the beginning of Keser Shem Tov a small section called “Tzavah M’HaBash’t zl’hh” in which the Baal Shem Tov outlines four key precepts for the chassidim.
I. To be simple and perfect in Avodas Hashem (Divine Service). Part of this is learning however much Mussar (Such as Mesilas Yeshorim) is needed daily; seeing to it always that we should cleave to good Middos (character traits) and proper behavior; never leaving a day without performing whatever mitzvos come to our path; looking to perform mitzvos all day, every day. Seeking to perform mitzvos leads to great clarification of the neshomo, leading to its proper illumination. So long as we keep mitzvos properly we won’t know any evil, since Hashem will protect us so long as we look from the beginning of the day until its end to perform whatever mitzvos come our way.
II. To be careful about Krias Sh’ma which is a huge thing, because if we can’t daven without machshovos zoros (foreign/improper thoughts) we can accustom ourselves to saying K’rias Sh’ma without such thoughts. There is a promise that someone who says K’rias Sh’ma properly will not be damaged physically or spiritually, meaning that those forces which lead to distracting thoughts in prayer will be prevented from interfering with us.I
II. To toivel (immerse) in a mikvah whenever possible, especially in needed times. I heard once in the name of the Satmar Ruv zt’l from the earlier tzaddikim that only through immersion in a mikvah can a Yid merit to Chein (grace/beauty). Kabbalah is referred to as Toras HaChein, so clearly immersion in a mikvah on a regular basis is the key to attaining levels in this Torah, and indeed all Torah.
IV. To keep Shabbos according to its halochos in all details. The sign given is “A person shall return until humility,” which through rearranging the letters for Shabbos we come to the word Toshav which is related to Teshuva, which is one way to understand why Chazal say that through keeping Shabbos even someone who does avodah zarah (idol worship) like the generation of Enosh.