Map out a tentative research plan. Doing so will give you direction and will likely spark more deliberate thinking about where to search. More suggestions on how to formulate a research plan may be found in the RA Resources guide.
Use a research guide from the Law Library, as well as those available on the NYU Library website and elsewhere online. Subject-based research guides have already pulled together key material on their topics. Consulting them can efficiently point you to the best sources. Oftentimes there will not be a research guide on the specific topic of your paper but there may be a research guide on the larger topic within which your paper falls. Guides can also be found through general internet searches, or through directories like Law Scout.
Ask for assistance early and often at the Reference Desk in the Main Reading Room. Librarians can suggest a strategy if you don't know where to start; advise you on hard-to-locate and hard-to-cite sources; confirm that you have exhausted all possible Library and publicly available resources; suggest services to acquire materials not held like ILL; and make arrangements to use other local libraries (required for most academic libraries), among other things. Note: You usually will not have check-out privileges at libraries under such arrangements.
Investigate content on more databases beyond just Westlaw, Lexis, and Bloomberg. While these are each deep and well-functioning legal databases, it goes without saying that many topics will need material from and citations to materials not available on those databases including monographs, articles, data, interdisciplinary articles, historical sources, and so on. Also, simply stepping out of the Westlaw, Lexis and Bloomberg Law box may spark crucial new ideas and directions. A helpful list of databases are available in the Law Library's A-Z list.
Sign up for current awareness services related to your topic. Current awareness services come in many forms--legal newsletters, new publication alerts, search alerts and so on. Alerts can potentially have a big long term payoff for the minimal work of setting up an alert initially. They can give you new ideas and keep you informed of developments as you write your paper. Understanding current developments in the area can also deepen your understanding of the subject area and enrich your insights for your paper.
Keep notes of where you’ve looked & search strings you used. It is helpful to maintain a research log (sample available in RA Training materials). Do this during preemption checks and during the main research stage. This will help you avoid having to duplicate your work unnecessarily. Further, when you are first starting a project, it is easy to not recognize the relevance of something you found that may be helpful upon later realization, given that one might not completely appreciate all the intricacies of the subject matter at that stage. Thus, if you don't maintain notes on your research trajectory, you may have difficulty retracing your steps where needed.
Try the Internet Archive for content that is no longer online. Sometimes, legacy materials may still be available by working backwards to locate the legacy URLs, especially those hosted by government bodies or institutions.
Update your research. For primary materials, the major legal databases will contain tools to check for currency and validity. These include Westlaw's KeyCite and Lexis's Shepardize. For secondary materials, setting up alerts from current awareness sources on your topic may be helpful.
How to determine when you are finished with your research? How does one determine the 'saturation point' for conducting comprehensive legal research? Research is an iterative process. It is often said that when your searches keep yielding the same results, you are finished. Another way to think about it: Are you getting so many repeat results that you believe that the chance that there is significant material out there that you haven't found is pretty small? Have you located the full range of primary authorities and authoritative secondary sources for your topic? Also, time permitting you might also continue to search during the writing stage. As your understanding of a topic develops, so will your ability to identify and find relevant material. You will gain a better sense of where to search and how to select keywords, which contributes to the iterative aspect of research.