Choose historically appropriate keywords. For example, use "Great War" instead of "World War I" to locate documents discussing the war during and just after it occurred.
Consider different terms that might have been used to describe the same event from opposing sides or perspectives.
Searching for the names of particular people or places may also be effective, but consider how the names might be presented (last name only, or as part of a title) and how country and city names have changed over time.
Use the date range feature in newspaper databases to narrow your search to articles published around the time of a significant event (battle, court case, etc.).
How to search Historical Newspapers to find information on kamikaze pilots in World War II:
How to search newspapers to find information on Syrian suicide bombers: