This task is assigned after my students have read silently. I don't assign this every day, however, I find it helpful when I feel my students need to be held accountable or when I want to get a sense of whether or not they are active or passive readers.
My students are asked to read and tag during their SSR. I have modeled during whole class read-alouds when it might be appropriate to respond to the texts, so they know to make a note when they make a connection or have an emotional response to and event or a character in their book. My students are to write what they are thinking in that moment and then stick it in their book. The next morning they attach their post-its to the sheet and choose one to log. This can also be something they share with each other in book clubs.