Rather than trying to construct one perfect search, plan on trying several experimental searches. As you search, seek out diverse perspectives by using a variety of keywords. Look for interdisciplinary perspectives on your topic by trying out your searches in more than one database.
Find one or more research guides related to your project. Choose a few databases and search tools and start exploring.
Turn your notes, ideas, and questions about your topic into keywords for search. If the database you are using has an "advanced search" use it! Advanced search will allow you to experiment with using a variety of keyword synomyms to explore your topic.
Most databases have a set of powerful filtering tools, usually on the left side of the screen when you search. Use these to refine your search results and learn new search terms.