1. Start big.
Search with the one keyword (or keyword phrase) that describes your most important topic idea.
If you get lots of search results, add in a keyword for the second most important idea. Adding more keywords means you'll get fewer search results.
If you get zero or very few search results with your one keyword, you know you haven't found the right word to search with yet, you misspelled something, or there is not a lot available on your topic. This is a good time to ask a librarian for guidance.
2. Use quotation marks.
Put quotation marks around keyword phrases.
Quotation marks tell search tools to find results containing keywords in the exact order as written, instead of searching for the words separately.
Your search results will be more relevant when you use quotation marks.
3. Try, and try again.
Finding good information - and learning research skills - isn't a one-and-done exercise. It is a process of continuous improvement that involves searching, reflecting, making choices and revisions, and searching again. Librarians call this process iterative searching.
The goal of iterative searching is to improve the relevancy of your search results in each iteration, and to learn along the way what strategies work best for you.