If we carry out a survey among teachers and ask them to portray their ideal classroom, it is very likely that one of the desirable ones includes the fact that a perfect class would be one in which students are attentive most of the time. It is true that it is difficult to prolong the interest constantly for several hours, we cannot forget that nobody keeps their attention curve at the same level every hour, not even every day.
Then how keep more interest and avoid classroom distractions as much as possible ?. It is very likely that the class calendar will need to be adjusted. In the early hours, students are more receptive and more attentive, quite the opposite of what happens late in the morning, where fatigue has left its mark. Subjects (Mathematics, Physics, languages, ...) and activities (an exam, for example) for which greater cognitive ability is required should be listed in the first hours of the daily agenda. For the end of the morning it is better to leave those that require the use of creativity (visual arts, multimedia, workshops, oral exhibitions,…) or those that serve for leisure and recreation (visits abroad, physical education,…).
On the other hand, it is important to know stimulate participation of the class when a subject is taught. There is nothing more soporific than listening to someone talk tirelessly for a long time without a chance to intervene. Pausing, making rounds of questions and answers, combining the word with visual presentations (infographics, videos, ...) and establishing an empathy with them, leaving a few minutes for them to feel free to explain themselves is a way of "awakening" their participation and reducing significantly the peaks of decline in the level of care.
Understand that Friday, as well as the days before vacations or holidays, are somewhat more complicated days because students are more tired, distracted, even more euphoric than usual. Being a little more condescending in these situations allows classes to not be a frustrating experience for either party.