Use quotes to lock down specific phrases: “microbial mats” “magnetic anomalies”. If you don't use quotes, the words can be found separately from each other.
Limit your keywords to specific database fields for greater focus. This forces your search term to be in a specific place (like the article title). Helpful if you get far too many results or if the keywords you're searching tend to appear in irrelevant places, like in the journal title or author.
Use a truncation symbol (*) to capture all word variants, eg sediment* for sediments, sedimentary, sedimentation, etc.
Use the OR connector to group related keywords or concepts: (RSL or “recurring slope lineae”); (microb* or microorganism*). Use parentheses if necessary to group your concepts together.
Use filters and facets – good options are by subject term, or by type of document (like scholarly journal article, dissertation, book chapter, or review article).
Limit to a date range that makes sense for your topic, if applicable.
Look at how your results are sorted. It’s usually by relevance, but not always. If they’re sorted by date instead, try changing the sort order.
Sorting by the number of times cited can be useful. This tells you that an article has been talked about a lot in the scholarly conversation. Being cited a lot doesn't necessarily mean it's a 'good' paper, just that other papers refer to it often. You have to read some of them to see the context in which they cite the paper.
Change up your keywords or add additional ones. Rephrasing your research question can help you choose keyword synonyms to replace or add on to your search. Having trouble coming up with new words to try? Look at popular sources or papers you've already found that match your topic to see what keywords they are using and give those a try.
Get familiar with your topic by using popular sources like wikipedia, news sites, or encyclopedias before searching for peer reviewed literature. It can be difficult to sift through scholarly articles to find what's relevant if you're not familiar with the foundational concepts of your topic. Use popular sources to gain familiarity with the general concepts and jargon before taking those ideas to a scholarly article database.
If you're not finding what you need, try searching multiple sources. If Web of Science isn't turning up results for you, try Scopus, ProQuest Central, Google Scholar, or the Library Search. There are hundreds of library databases available to you. See the research guide for your discipline to look at curated lists of library resources, or contact your librarian to talk about your options (links below!).
Consider broadening or refining your topic further. If you're looking for something specific and you're not finding it after checking multiple sources for scholarly articles on the topic, you may have found a gap in the literature. This can be great for finding a research thesis topic to explore, but maybe not so much for a term paper due in a couple weeks. Refine your topic to fit your needs based on the available literature.