Before you start searching on your topic, it's helpful to consider the various possible keywords you could use  because the terms we automatically think of may not be the ones experts use when they write about our topic. And if we don't use the keywords experts use in our searches, we won't pull up their articles. This two-minute video from Portland State University will teach you how to brainstorm keywords:

You can identify additional keywords by looking for a Wikipedia entry on your topic or doing a Google search on your topic and seeing what related or similar words are used in the titles of results. Try to think of as many synonyms or related terms as you can.

Here's an example research question: Does the presence of a smartphone impact people's ability to pay attention in face-to-face conversations?

The most important keywords are smartphone, attention, and face-to-face conversations. Now, I will brainstorm other keywords that are similar to those original terms:

       Smartphone: cell phone, mobile phone, mobile device

       Attention: concentration, distraction, listening, focus, distraction, listening

       Face-to-face conversation: face-to-face interaction, face-to-face communication, face-to-face dialogue

Your topic may not require brainstorming as many keywords and, in some cases, you may brainstorm even more.