Two Label Scenario: Tip#1: You can apply as many labels as you want to an email.
Let's say you receive an email from parents and you keep a label for each parent conversation you have going. You are also working on a longer term project with students called Project X. When a parent emails you about Project X you may want to apply the Project X label and the Parent Name Label as well. Now when you look in the label Project X, that email will be on the list as well as in the Parent Name label as well.