Once you have developed your research question, you'll need to determine your inclusion/exclusion criteria - these are the characteristics which make a study eligible or ineligible to be included in your review. Here is an example of some of the common inclusion/exclusion criteria used in systematic reviews, which include:
In many cases, you can use the limits or advanced search features in many of the Library's databases to apply your inclusion/exclusion criteria , e.g., limiting your results by year of publication, language, etc.
It is recommended that a review protocol also be prepared, which is essentially a planning document that indicates how your review will be carried out. Here is an example of the University of Warwick's protocol template.
The Cochrane Collaboration has an online module to help reviewers prepare their protocol in accordance with the organization's standards.