Once you have a general topic in mind, brainstorm 5-10 related search terms BEFORE you start your research. This will help you define your research question.
For example: Search terms for Video Games could include types of games such as simulation or first-person shooter. Search terms for Video Games could also include related words or terms about the experience like relax(ation), education(al) or benefits, problem-solving, or harm. Search terms can also include names of people, events, or places: while researching Video Games you could use terms like Call of Duty, Zelda, or Gamergate.