In essence, finding articles in databases often involves a two-step process: 1) Selecting database; 2) Constructing a search string within that database.
Database Selection Tips
Keep a detailed log of which search strings you used in which databases. This is helpful to keep track and also encourage you to think sequentially and creatively about how you are searching. Also, you can show it to others, including reference librarians, who might be able to suggest other databases to try or other search terms/strings.
In essence, finding articles in databases often involves a two-step process: 1) Selecting database; 2) Constructing a search string within that database.
Searching Tips
Adjust Your Search String. If your search string results in too many results to wade through: 1) Analyze the results. Are there a lot of false hits? Is there a way to rework the search string or keywords to avoid the false hits? Is there a unique keyword that would likely be in a relevant article but would not necessarily be in the false hits? Is the topic too broad? 2) Try using boolean operators (e.g. proximity, "but not") to focus results, if those features are available in the database you are using. If your search string results are too few, consider if additional search terms can be added to your search string. Try loosening boolean operators if you used them. Should your topic be broadened?
Leverage an On-Point Article: You can often use one on-point article to find more. If you have an on-point article: 1) Mine the article's footnotes for other relevant sources; 2) See what other articles cite the on-point article; Some databases will have a "citing articles" feature (or similar term). You can also run manual searches for other articles citing an article. When you do that, be mindful of various citation formats. It's often a good idea to search for the title of the piece, because that tends to be consistent field across citation formats. 3) Evaluate the relationship between search terms in the relevant piece and use that analysis to adjust your search string for new items. 4) Look at the article-author's other publications. Some authors will approach the same topic from more than perspective in multiple publications. Online CVs or scholarship repositories can help.
Search Fields. Some databases allow you to search fields or segments in an article or secondary source, such as the title or abstract. Searching fields, particularly title field and abstract, can be a high-level method to quickly find relevant articles. One example of of advanced search features is on Google Scholar's Advanced Search page. HeinOnline permits title searching.
Use an Index (or Database That Utilizes Index/Subject Tags): Use a database (like EBSCO's Legal Source) that provides subject tags for articles. When you find an on-topic article, click on the link for the subject tag to find other articles with that tag. Or if appropriate, use a database (e.g. EconLit and SSRN) that permits searching or browsing by JEL code.
Ask a reference librarian for assistance in modifying your search string. Come to the reference desk with some ideas for key terms.