The Rebbe stresses the absolute necessity of studying Chassidus, citing strong sources, including the Arizal and Vilna Gaon. To avoid distracting thoughts in prayer, he advises limiting idle talk, praying and learning from a text, maintaining purity, giving tzedakah before Shacharis, and accepting the yoke of Heaven before Torah.
https://www.torahrecordings.com/rebbe/igroskodesh/015/012/5653