All databases have readily available onscreen help information to assist in constructing more complex searches using different fields or by using eg: Boolean and proximity operators, and truncation and wildcards.
Alternative Terminology & spelling: consider also using alternative terminology in your searches such as synonyms and use spelling variations (example: labour / labor)
Using Subject Headings - if you find a good article, use the SUBJECT headings to find more articles.
Be aware of the date ranges of databases. Most databases commence in the early to mid-1980s – so if you are looking for earlier legal periodicals, try including eg: 1) Index to Legal Periodicals Retrospective in your searches - this database indexes articles from the first volume of each journal title in the database; and 2) HEIN Online Law Journal Library which contains the full text of all articles from the first volume of every journal in the database.
Bibliographies in Retrieved Articles/Books: use the bibliographies in relevant articles and books to find earlier relevant articles etc.
Alerts: When using databases, you can often set up alerts for saved searches once you have conducted a search. Learn how to set up an alert by referring to the research guide Keeping up to date in Law.