Are you studying mathematics and writing a bachelor's or master's thesis? Are you working on a seminar paper or even a mathematical book? In the end, the success of your work depends on whether you can express your thoughts clearly and engagingly on paper, in good style. Good style is immediately recognizable. However, the paths to achieving good style are somewhat longer and raise many questions: How can a formula be made clear and how should it be numbered? How do you find good names for mathematical objects and where should they be introduced? What does a well-written proof look like? Which literature should you avoid citing, and for whom are you actually writing a bachelor's thesis? This reliable companion answers these questions and many more. The answers are summarized in clear rules and guidelines. All questions regarding formatting are also addressed in LaTeX.