Secondary school teachers have quite busy and complex routines in their classrooms. However, present classroom technologies usually require focused attention from teachers while being interacted with, which restricts their use in teachers' daily routines. Peripheral interaction is a human-computer interaction style that aims to enable interaction to take place both in the center and periphery of users' attention and naturally shift between the two. We believe that classroom technologies employing the principles of peripheral interaction can reduce attentional resources required for teachers to interact with the technologies, and thus make technologies seamlessly blend into teachers' routines. In order to design such technologies, a thorough understanding of users' existing routines is crucial. In this paper, we present a qualitative study on everyday routines of seven Dutch secondary school teachers using context mapping methodology. The results of two qualitative content analyses reveal an overview of teachers' routine tasks in their classrooms, as well as rich and vivid contextual information about how teachers allocated their attention in their routines and how teachers experience their routines. Based on these findings, we present opportunities and considerations that may inform the design and development of classroom technologies which are to become part of teachers' routines.