First, learn where to search. UCLA subscribes to about a thousand databases, and each has its own search engine which looks for different things. Don't look for article titles in a book catalog, or vice versa. And don't search for the title of an individual work in a site search box!
Second, learn what words the search engine is looking for. Most databases are not searching the full text, they're only searching metadata like title, subjects, and abstracts. Unless you know what types of metadata a database includes, you won't know what types of words to search for.
Finally, learn the more advanced search techniques like controlled vocabularies, Boolean logic, and truncation symbols. These options aren't present in all search engines, and are implemented differently in each database, but knowing what to look for will let you take advantage of them.
Once you know how to use these techniques you'll find your research gets a lot easier. And you'll be able to impress your TAs and professors, especially when you learn the dirty little secret of academia: most of your professors suck at searching almost as much as you!