Always make sure you are familiar with the various keywords associated with your topic before beginning your research. This includes both the formal and informal terms that are used to describe it. Here is an example of the difference between searching for "frozen shoulder" (a general description that can apply to several conditions) versus "Adhesive Capsulitis" (a much more specific condition) in four different databases.
Identify keywords that relate to your topic to assist you when you are searching for resources. Often different words can describe the same concepts and as a researcher, you can never be sure which keywords will bring back the information you are looking for.
Brainstorm related terms, broader terms and narrower terms related to your topic.