The lectures class offers extras for drafting good-looking lecture notes, such as several theorem environments and automatic spacing and alignment of figures. The two-page example has a title page listing the authors, professors, credits and course, in this case at the Università degli studi di Milano, then sample maths and a boxed Pythagorean theorem. All names are placeholders and no other packages are needed.
Shared under the MIT License. All credit to Luca Cappelletti; the licence comes with the project's files.