Like a cluttered desktop, a cluttered phone screen can create an unconscious stress trigger every time you look at your phone.
Think about your apps in terms of frequency of use…you probably want those that are used multiple times daily stored on the very first screen you see when you unlock your phone.
Sort remaining apps by types into folders of overarching categories (entertainment, health, business, etc).
Delete apps you no longer use.
P.S. Check out this Mashable article for further inspiration as to how to categorize, label, and organize these folders.