A useful trick is to "mine" the citations of an article for additional sources. If you find an article that has information that pertains to your topic, look through the sources that are in the reference list. This will help you find similar research and also to situate the source you are reading in the wider scholarly conversation.
Start with a Broad Search
When you are starting your research it is a good idea to start with a broad question and narrow it down as you go. You can narrow your search by adding additional keywords, using the "filter results" options, or searching in a subject specific database.