One is to listen when students come into classroom with issues or big sigh... usually means there is something going on with them... or if a student slams his book down on the desk or slams the door etc... student is carrying extra axiety around... we need to be more alert.

Or when a student start missing classes there is usually personal issue going on at home and see if there is solution for the student so he/she does not miss a lot time getting the work done.

Medical issue going on medications are not working again they seem unfocused in class or staring out the window a lot is another indicator something is not well with the student.

You need to walk softly and listen to student story all of it and not interupt until they are done.. and go from there. Interupting a student when they are speaking is rude and student does not/will not feel heard and then leads to not caring etc..