The practice Breslov is known for is hitbodedut, secluding oneself. An hour a day, ideally in a field or somewhere else nobody is listening, spent speaking aloud to God in ordinary spoken language rather than in the fixed liturgy: complaining, asking, arguing, saying whatever is actually there. Nachman treated this as the central work and not as a supplement to prayer, and the insistence on the vernacular is the point, because a person who must translate into a sacred register has already started performing.
The teaching arrives in two very different literatures. Likutey Moharan is the collection of his discourses, dense, associative, built out of verses and rabbinic passages brought together in ways that do not announce their logic. The Sippurey Maasiyot are thirteen long stories, about lost princesses, exchanged children, a beggar with no hands, told without any interpretation attached. Nachman told them late, said that they were how he would reach people who could no longer be reached directly, and left the reader to do the work.
Two further emphases run through both. One is simcha, joy, treated as an obligation and a discipline rather than a mood, with despair named as the real danger. The other is simplicity: the doubts are not to be resolved by argument but outlasted, and the person who keeps going without an answer is doing the thing correctly.