Use keywords.
Combine keywords with boolean operators (AND, OR, NOT).
If your research involves a company, search by the ticker symbol of that company, if available.
If you are doing industry research, search by industry code when possible.
These databases are a great place to start as they cover a wide range of business-related topics. They provide access to articles and some non-journal content (company profiles, industry profiles, market research reports, SWOT analyses, country reports, etc.).