Always think about synonyms.
Start with keywords to describe your topic, within results, read the abstract and look at the subject headings to identify additional keywords to use and revise the search (if needed).
Start with keywords (place phrases in quotes), use connectors (or / and) and look for the subject headings specific to each database.
|"foreign policy"||"human rights"|
|"transnational security"||"middle east"|
|"political participation"||"border security"|
|"voting rights"||"nuclear weapons"|
|environment* = environment or environments or environmental||intervention* = intervention or interventions|
|risk* = risk or risks||immigra* = immigrant or immigrants or immigration|
|threat* = threat or threats||terroris* = terrorist or terrorists or terrorism|
use - or - to connect synonyms or like concepts
any of the words can be present
"middle east" or "arab state" or yemen or egypt
globalization or multinational
"social media" or twitter or facebook
policy or policies
use - and - to connect concepts
all terms must be included
("world hunger" or "global hunger") and gmo*
("counter terrorism" or counterterrorism) and ("social media" or twitter or facebook)
"foreign policy" and china
immigra* and (policy or policies or legislation)
|law and legislation|
|policy or policies|
In addition, you can search by a known author.