I encourage all of my students to follow this naming convention when they go to name the document:
Unit - Brief name of task - full name of student
For example I might get a student to name their document 2.5 Notes Catherine Wooller The 2.5 referring to our unit, the notes referring to what document it is and their name.
To eliminate the situation where you are receiving emails from students sharing work with you I would encourage you to set tasks through google classroom as an assignment. Keep an eye out for an upcoming post on how to do this.