There are two threads linking effective lectures and effective technology use. The first is consideration of what students bring to the table in terms of goals, interests, and prior knowledge. The second is the deliberate management of the opportunities for students to engage with content in order to focus their investment of mental effort on key ideas. In educational research, a powerful framework for considering these factors jointly is cognitive load theory (CLT). This article discusses how to effectively apply and manage cognitive load theory in teaching. In order to optimize the benefits of instruction, CLT prioritizes available information according to the type of cognitive load it imposes. Because the central premise of CLT is to optimize the allocation of students' working memory resources for mastering particular information, the author emphasizes that it is vital to identify very specifically what the instructional objectives are for the course as a whole and for each class meeting or module. Teaching effectively and using cognitive load theory to guide practice is challenging. It requires the focused consideration of many details regarding the students, their knowledge, and their instructional goals. (Contains 11 resources.)