Controlled Vocabulary: Use Controlled Terms, Descriptors, Subject Headings and/or Identifiers to look for all items on the same topic. These are terms selected by an indexer so that all articles on a topic will come up even if the author used a different word to describe it. Search the Thesaurus (when available) to find terms that are broader, more specific or related.
When there is no Thesaurus easily available: search for an article you are already aware of, or do a broad search for your subject to find an article about what you're interested in, open the record to see what terms the article is indexed under. They may be listed as subjects, keywords, or both. Use these terms to narrow your search. In some databases these terms may be clickable allowing you to see all articles indexed with a specific term.
+ or AND: Use + or AND between search terms to retrieve ALL of the words in each record. Many databases default to an AND search if you simply type words in to a search.
OR: Use OR to search synonyms or alternate words on the same topic. Or is used to expand the number of records retrieved in a search. When searching with OR the terms must be put in one search box together or grouped with parenthesis e.g. (Pets OR Cats OR Dogs)
- or NOT: Use - or NOT between search terms to exclude ALL of the instances of the word following - or NOT from your search. (Use this only when absolutely necessary it is easy to exclude good results along with the bad using this technique.)
"Phrase Searching": putting quotes around a phrase tells the computer to look for the exact words next to each other in that order.
Truncation (*): Use the truncation/wildcard symbol to search different forms of a word. For example, engin* will retrieve Engineer, Engine, Engineered, Engineering, etc.
Citation Chaining: One of the most underused techniques when searching for articles is citation chaining. There are two ways in which you can follow citation chains.
Forward Chaining: This method works best when you have an article that is highly relevant, the older the article the more likely it is to have been cited. Web of Science allows you to search how many times an article has been cited, this allows you to see who built upon the work of the original article.
Backward Chaining: This method works with any article. By noting where citations occur and consulting the bibliography of an article you can discover past works that you should review and cite in your own work. It is important to pay attention to both the titles of the works cited and where works are cited in the text because some titles may not look relevant to your own work but may be cited in a way that indicates they are highly relevant.
Demystifying Dissertation Writing : A Streamlined Process from Choice of Topic to Final Text by Blog posts by Dr. Raul Pacheco-Vega:
Science Research Writing for Non-Native Speakers of English by 
