Keep it simple.
You want to include only a few (2-3) words in your searches - the things that that get the heart of what you're looking for
What is the relationship between amount time spent on social media and likelihood of an eating disorder?
How was JFK's foreign policy influenced by his religious faith?
Build off these main topics
Consider synonyms/Related Words
Look at Wikipedia/Credo Reference/CQ Researcher
Start broad, then narrow down based on what you're seeing
Google Scholar is a great resource for finding scholarly resources. It is also a great place to check for the full-text of an article before submitting an ILL request.